High Court of Australia Mason A.C.J. Murphy, Brennan, Deane and Dawson JJ. R v Coldham; Ex parte Australian Workers' Union [1983] HCA 35 ORDER Order nisi for prohibition and mandamus made absolute. Cur. adv. vult. The following written judgments were delivered:— 1983, Oct. 11 Mason A.C.J. and Brennan J. We agree with the reasons for judgment of Deane and Dawson JJ. and with the orders which they propose. However, we prefer to express our own reasons for concluding that s. 60 of the Conciliation and Arbitration Act 1904 Cth, as amended, is no bar to the relief which is sought by the prosecutor. The jurisdiction of the Court conferred by s. 75(v) of the Constitution to grant mandamus and prohibition directed to an officer of the Commonwealth cannot be ousted by a privative clause. However, it has been established by a long course of judicial decisions in this Court that a privative clause in the form to be found in s. 60 of the Act will validate an award or order of the Commission, so far as it can do so constitutionally, provided that three conditions are fulfilled " namely that the purported exercise is a bona fide attempt to exercise the power, it relates to the subject matter of the legislation, and it is reasonably capable of being referred to the power (i.e. does not on its face go beyond the power) " to use the words of Kitto J. in Reg. v. Commonwealth Conciliation and Arbitration Commission; Ex parte Amalgamated Engineering Union (Australian Section) [1] . See also R. v. Hickman; Ex parte Fox and Clinton [2] ; R. v. Metal Trades Employers' Association; Ex parte Amalgamated Engineering Union, Australian Section [3] ; Reg. v. Members of the Central Sugar Cane Prices Board; Ex parte Maryborough Sugar Factory Ltd. [4] ; R. v. Murray; Ex parte Proctor [5] ; Coal Miners' Industrial Union of Workers of Western Australia v. Amalgamated Collieries of Western Australia Ltd. [6] . 1. (1967) 118 C.L.R. 219, at pp. 252-253. 2. (1945) 70 C.L.R. 598, at pp. 614-615. 3. (1951) 82 C.L.R. 208, at p. 249. 4. (1959) 101 C.L.R. 246, at p. 255. 5. (1949) 77 C.L.R. 387, at pp. 398-399. 6. (1960) 104 C.L.R. 437, at pp. 442-443. As Dixon J. explained in Murray [7] , and in other cases, it is a matter of reconciling the prima facie inconsistency between one statutory provision which seems to limit the powers of the Tribunal and another provision, the privative clause, which seems to contemplate that the Tribunal's order shall operate free from any restriction. The inconsistency is resolved by reading the two provisions together and giving effect to each. The privative clause is taken into account in ascertaining what the apparent restriction or restraint actually signifies in order to determine whether the situation is one in which prohibition lies. 1. (1949) 77 C.L.R., at pp. 398-399. The object of a provision of this kind is generally to protect the award or order from challenge. Consequently, the making of the award or order is the occasion for taking the privative clause into account in interpreting the Tribunal's authority or power more liberally. Before the award or order is made the Tribunal will be held to a strict construction of its powers uninfluenced by the clause, thereby enabling the grant of prohibition, notwithstanding that had the proceedings reached the stage when an award or order was made prohibition could not have been obtained. But a clause like s. 60 cannot affect the operation of a provision which imposes inviolable limitations or restraints upon the jurisdiction or powers of the Tribunal. In the face of such a provision, a clause like s. 60 is ineffective to prevent prohibition going when the Tribunal transgresses those limitations or restraints (see per Dixon J. in R. v. Metal Trades Employers' Association [8] ; and per Latham C.J. and Dixon J. in R. v. Commonwealth Rent Controller; Ex parte National Mutual Life Association of Australasia Ltd. [9] ). The present is just such a case. The terms of s. 142A(1) are quite explicit. The Commission is authorized to make an order that an organization of employees shall have the right to represent a class or group of employees who are eligible for membership of the organization to the exclusion of any other organization. Section 142A neither expressly nor impliedly confers jurisdiction on the Commission to give a binding decision on the question whether persons are eligible for membership of an organization. The entitlement of a person to be admitted as a member of an organization of employees is a matter that falls within the jurisdiction of the Federal Court (s. 144(5), (5A) and (6)). Indeed, we are unable to perceive how the Commission could be given authority to determine conclusively the question of eligibility for membership consistently with its character as a body which does not exercise the judicial power of the Commonwealth. 1. (1951) 82 C.L.R., at p. 248. 2. (1947) 75 C.L.R. 361, at p. 369. The basis of the decision in Reg. v. Marks; Ex parte Australian Building Construction Employees' and Builders Labourers' Federation ("the Omega Case") [10] underlines the point. Fundamental to the conclusion that s. 142A did not vest judicial power in the Commission was the proposition that it could not give a binding decision of eligibility for membership. That, so the Court held unanimously, was a jurisdictional fact reviewable by prohibition [11] . 1. (1981) 147 C.L.R. 471. 2. (1981) 147 C.L.R., at pp. 488-489. In the result the order nisi for prohibition and mandamus should be made absolute. Murphy J. This is a demarcation dispute between two long established federal unions, the Australian Workers' Union ("the A.W.U.") and the Australian Building Construction Employees' and Builders Labourers' Federation ("the B.L.F.") about which union should represent workers in certain construction work on a proposed bauxite mining site and alumina refining project in Western Australia. The B.L.F. obtained from the Australian Conciliation and Arbitration Commission an order giving it the exclusive right of representation. Section 142A(1) of the Conciliation and Arbitration Act 1904, as amended, ("the Act") provides that: The Commission may, on the application of an organization, an employer, the Minister or the Bureau, if it thinks it in the public interest to do so, make an order providing that an organization of employees shall have the right to represent, in respect of all or some industrial interests under this Act, a class or group of employees who are eligible for membership of the organization, either generally or subject to such limitations as it may specify, to the exclusion of another organization or organizations and may make such orders as it thinks necessary in consequence of such an order (my emphasis). The A.W.U. contends that the Commission could only make an order under this section if the persons engaged or to be engaged in the disputed work were in law and fact eligible to be members of the B.L.F. It submits that the Commission erroneously held that they were eligible; that by reason of this error the Commission acted without jurisdiction, and that further proceedings upon its order should be prohibited. The A.W.U. further claims that the Commission erroneously held that the persons were not eligible to be members of the A.W.U. and that mandamus should issue to correct this error. However, s. 60(1) of the Act provides: Subject to this Act, an award (including an award made on appeal) — (a) is final and conclusive; (b) shall not be challenged, appealed against, reviewed, quashed or called in question in any court; and (c) is not subject to prohibition, mandamus or injunction in any court on any account. An award includes an order (s. 4(1)). Section 60 is part of a legislative policy for preventing interference by the courts, in particular the High Court, with the Australian Conciliation and Arbitration Commission. This policy has been a permanent feature of the Act (see Reg. v. Moore; Ex parte Victoria [12] ). 1. (1977) 140 C.L.R. 92, at pp. 106-107. An award or order by an officer of the Commonwealth which exceeds the legislative powers of the Commonwealth cannot be authorized by s. 60 or any other law. It cannot be immunized from the constitutional writs of mandamus, prohibition or injunction (Constitution s. 75(v)). However, within constitutional limits the Parliament can make the power or authority of such an officer elastic, and not subject to objectively fixed restrictions or conditions. Elasticity might be achieved by authorizing the award or order if the officer were satisfied or of the opinion (in good faith) that certain conditions existed. Does s. 60 have a similar protective operation upon the action of officers acting in good faith outside the conditions which, apart from s. 60, would limit their authority? In other words, can s. 60 stretch the jurisdiction which would otherwise be taken to be conferred by a provision such as s. 142A? The prosecutor contends that s. 60 has no such protective or curative operation. In the Omega Case (Reg. v. Marks; Ex parte Australian Building Construction Employees' and Builders Labourers' Federation [13] ) Mason J. for the majority stated: "Obviously the Commission has to decide for itself the question of eligibility for membership, but the status of its finding on that point is that of a finding as to a jurisdictional fact, one which is capable of review on prohibition under s. 75(v) of the Constitution." However, as I pointed out in Reg. v. Williams; Ex parte Australian Building Construction Employees' and Builders Labourers' Federation [14] , the respondents' counsel in the Omega Case did not rely on s. 60, but conceded that if the Commission were in error prohibition should issue. 1. (1981) 147 C.L.R. 471, at p. 489. 2. Ante 402, at pp. 412-413. In Waterside Workers' Federation of Australia v. Gilchrist, Watt & Sanderson Ltd. [15] referring to the then s. 31 (a predecessor of s. 60) Isaacs and Rich JJ. said: Unless the doctrine that even the express words of Parliament are not sufficient for the purpose is to be the rule of this Court, we can see no loophole in sec. 31(1) whereby prohibition or certiorari can creep in for any statutory defect once an award is duly made and perfected. The mere use of the word "prohibition" seems decisive — for there is no room for its exercise except for lack of jurisdiction. Again, the words "on any account whatever" challenge the ingenuity of the draftsman to find any expression more complete. 1. (1924) 34 C.L.R. 482, at p. 526. In R. v. Hickman; Ex parte Fox and Clinton [16] , Dixon J., in referring to reg. 17 of the National Security (Coal Mining Industry Employment) Regulations (a provision identical in substance to s. 60) said: But where the legislature confers authority subject to limitations, and at the same time enacts such a clause as is contained in reg. 17 it becomes a question of interpretation of the whole legislative instrument whether transgression of the limits, so long as done bona fide and bearing on its face every appearance of an attempt to pursue the power, necessarily spells invalidity. 1. (1945) 70 C.L.R. 598, at p. 616. There is much authority in favour of the proposition that such clauses mean that where a tribunal "has made a bona-fide attempt to exercise its authority in a matter relating to the subject with which the legislation deals and capable reasonably of being referred to the power possessed by the tribunal, the acts of the tribunal shall not be invalidated and accordingly shall not be the subject of prohibition" (R. v. Murray; Ex parte Proctor [17] , Dixon J.; Reg. v. Commonwealth Conciliation and Arbitration Commission; Ex parte Amalgamated Engineering Union (Australian Section) [18] ; R. v. Metal Trades Employers' Association; Ex parte Amalgamated Engineering Union, Australian Section [19] ; Reg. v. Central Sugar Cane Prices Board; Ex parte Maryborough Sugar Factory Ltd. [20] ; Coal Miners' Industrial Union of Workers of Western Australia v. Amalgamated Collieries of Western Australia Ltd. [21] ). 1. (1949) 77 C.L.R. 387, at p. 398. 2. (1967) 118 C.L.R. 219, at pp. 252-253. 3. (1951) 82 C.L.R. 208, at p. 249. 4. (1959) 101 C.L.R. 246, at p. 255. 5. (1960) 104 C.L.R. 437, at pp. 442-443. In Hickman and in R. v. Central Reference Board; Ex parte Thiess (Repairs) Pty. Ltd. [22] , the Court held that the expression "coal mining industry" formed a final and definitive limitation upon the powers, duties and functions of the tribunals in question. It is understandable that the legislature should intend a body acting under a delegated legislative scheme confined to the coal industry to be itself confined to the industry, notwithstanding privative provisions similar to s. 60 (see also R. v. Drake-Brockman; Ex parte National Oil Pty. Ltd. [23] ). 1. (1948) 77 C.L.R. 123. 2. (1943) 68 C.L.R. 51. The authority in s. 142A is altogether different from the power considered in Hickman and Thiess . Here the Commission is intended to have power to demark industrial interests of organizations of employees generally without any limitation to any particular industry or category of industry or of employment. An error about eligibility for membership of the applicant organization does not take the Commission right outside the scope of demarcation. The Commission's decision was an honest attempt to exercise its power and reasonably capable of reference to the power given to it by the legislation. In the circumstances Dixon J.'s test invites interpretation of the whole Act to determine "whether transgression of the limits, so long as done bona fide and bearing on its face every appearance of an attempt to pursue the power, necessarily spell invalidity" (Hickman's Case [24] ). The Parliament clearly intended that demarcation disputes, which have been notorious for their hair splitting points of contention should be dealt with by a specialist body (see Report of the Committee of Inquiry on Co-ordinated Industrial Organizations (1974) (the Sweeney Report), pp. 33-37, 53-54; Wright, Job Demarcation As Industrial Conflict: A Critical Review (1980)). 1. (1945) 70 C.L.R., at p. 616. If s. 60 does not protect bona fide attempts by the Commission to exercise jurisdiction under s. 142A, every demarcation order would be open to challenge in this Court on the ground that notwithstanding its good faith attempt, the Commission has misconstrued the eligibility rules of an organization, in whose favour, or against which, the order was made. This would work much public mischief, by delaying and confusing the resolution of disputes. Further, this Court would become, in practice, the court of immediate resort for deciding eligibility for membership of federal trade unions. Even if this Court were able to remit such matters to another court this would only transfer the problem. It is difficult to accept that Parliament intended such consequences. Rather, Parliament's intention was that s. 60 should operate so as to extend the jurisdiction under s. 142A to empower good faith attempts to exercise it. Bath states: "Australian courts continue actively to maintain the distinction between jurisdictional and non-jurisdictional error of law, and are, generally speaking, not anxious to intervene in the decisions of inferior courts or tribunals on the ground of jurisdictional error. The exception to this general proposition is the industrial cases, where intervention has been common, and minor errors have been described as going to jurisdiction" ("The Judicial Libertine — Jurisdictional and Non-Jurisdictional Error in Australia ", Federal Law Review, vol. 13 (1982), p. 13). The orders of the Commission are not conclusive of the eligibility of persons for membership of an employee organization. There are methods (other than constitutional writs) for determining such questions judicially, for example in the Federal Court (see s. 107 of the Act (reference of questions by Commission to Federal Court); s. 112 (reference of questions of law by Registrar to the Federal Court); see also s. 144(5), (5A) and (6)). But, if the Federal Court, whether on reference to it or in some other proceeding, decided that the persons in question were or were not eligible to be members of a particular organization, this would not be subject to appeal to this Court (see s. 114(1)). Also, the Federal Court's order would not properly be the subject of mandamus, prohibition or injunction; for mere error of law does not found these writs (Reg. v. Williams; Ex parte Australian Building Construction Employees' and Builders Labourers' Federation [25] ; Reg. v. Dunphy; Ex parte Maynes [26] ; Houssein v. Under Secretary, Department of Industrial Relations and Technology [27] ). 1. Ante, p. 413. 2. (1978) 139 C.L.R. 482, at p. 497. 3. (1982) 148 C.L.R. 88, at p. 95. In R. v. Taylor; Ex parte Professional Officers' Association — Commonwealth Public Service [28] Latham C.J. observed that the Industrial Registrar in deciding "may give a wrong decision or a right decision. There is no appeal to this court from his decision." Dixon J. said the Registrar " is engaged upon the very function assigned to him and none the less so because he may arrive at an erroneous conclusion. An officer may decide a matter before him wrongly without exceeding his power". And went on [29] : I think that the policy of the Act is that matters of this description should be dealt with by the Court of Conciliation and Arbitration and by its officers and that we should be very careful in maintaining the distinction between error in deciding a matter and excess of power so that we do not award a writ of prohibition in matters which are within the province of the court and of the Registrar to decide. We should be careful to exclude from our consideration matters which go to the correctness or incorrectness of the decisions of the Registrar or of the court when we are called upon to decide whether they have exceeded power. 1. (1951) 82 C.L.R. 177, at p. 184. 2. (1951) 82 C.L.R., at p. 186. This warning was repeated in Reg. v. Moore; Ex parte Co-operative Bulk Handling Ltd. [30] by Gibbs C.J., Murphy, Aickin, Wilson and Brennan JJ. 1. (1982) 56 A.L.J.R. 697; 2 I.R. 1; 41 A.L.R. 221. These considerations emphasize that s. 60 should be given a beneficial construction which would protect good faith attempts by the Commission to exercise its jurisdiction in demarcation disputes. It was argued in this case that s. 60 did not apply because the orders have not been drawn up. However, the legislative policy expressed in s. 60 should not be defeated merely by the procedural device of making an application after order but before the formalities are complete. The orders nisi should be discharged. Deane and Dawson JJ. The Australian Workers' Union ("the A.W.U.") applies to make absolute an order nisi for prohibition and mandamus. The respondents to the application are the members of a Full Bench of the Australian Conciliation and Arbitration Commission ("the Commission") and the Australian Building Construction Employees' and Builders Labourers' Federation ("the B.L.F."). The proceedings arise from a decision of the Commission to make an order pursuant to s. 142A(1) of the Conciliation and Arbitration Act 1904 Cth ("the Act") granting to the B.L.F. "the exclusive right of representation" of employees engaged in certain disputed areas of construction work on the site of a proposed bauxite extraction and refining project at and near Worsley in Western Australia. The Commission reached that decision after a hearing of related applications which involved both that project and a similar project at Wagerup in Western Australia. Construction work was largely completed at Wagerup and the Commission concluded that the only order it should make as regards that site was an order that the A.W.U. represent the employees in concrete batching plants. While the Commission's decisions as to Wagerup are not challenged in these proceedings, some of the evidence relating to that project is of more general relevance and has been before the Court on the present appeal. The Worsley project is a joint venture of Reynolds Australia Alumina Ltd., The Shell Co. of Australia Ltd., Dampier Mining Co. Ltd. and Kobe Alumina Associates (Australia) Pty. Ltd. Those venturers have appointed Worsley Alumina Pty. Ltd. as their project manager and that company has in turn engaged Raymond Engineers Pty. Ltd. as construction manager. The construction manager does not itself employ workers engaged in the actual construction work but relies upon independent contractors and their sub-contractors to carry out various portions of the work. There are two separate sites, namely, the site of the bauxite mine which is situated at Saddleback some fifty kilometres from Worsley and the site of the alumina refinery where the bauxite will be treated and refined and which is at Worsley itself. The mine site will be linked to the refinery site by a conveyor belt, along which the crushed ore will be transported to the refinery, and by a road. The construction work at both refinery site and mine site is in progress but substantial construction work remains to be completed before the extraction and treatment of bauxite can commence. The construction work at the mine site includes the construction of offices, workshops and amenities buildings, sewerage, storage tanks, fencing and roads. At the refinery site, it includes the construction of similar buildings and facilities and of a power plant, refinery tanks, water-works, railway sidings, bridges and pipe racks. The construction work in relation to the Worsley project also involves the construction of the connecting conveyor and work in two concrete batching plants. Each of the A.W.U. and the B.L.F. applied to the Commission for orders under s. 142A(1) of the Act, providing that it should have the exclusive right to represent certain classes or groups of employees engaged in construction work on the Worsley project. Each organization claimed that the relevant workers are eligible for membership of itself and disputed that they are eligible to become members of the other. The Commission found that the workers at the two concrete batching plants are eligible to become members of each organization and that the remainder of the workers involved are eligible to become members of the B.L.F. but not of the A.W.U. As a result of those findings the Commission indicated that it would make an order pursuant to s. 142A(1) giving the A.W.U. the exclusive right to represent employees in concrete batching plants and an order granting to the B.L.F. the exclusive right of representation of the remainder of the workers involved. It is not necessary, for the purposes of the present application, to examine in detail the precise nature of the work performed by the various groups of workers whose representation would be affected by the Commission's proposed order in favour of the B.L.F. which is the subject of challenge in the present application. Putting to one side the employees in concrete batching plants whose representation is not presently in issue, the workers in question ("the relevant workers") are employed either by one or other of the various independent contractors engaged by the construction manager to carry out the various facets of the overall construction of mine, refinery and associated facilities or by a sub-contractor engaged by one or other of such independent contractors in that regard. The major contractors are large construction companies which also carry out various types of large-scale construction work in places other than Worsley. Some of the relevant workers were employed by their employer contractor or sub-contractor before, and independently of, their coming to the Worsley project. The great majority were, however, employed for the purpose of performing their present work in relation to that project. The nature of the work performed by the relevant workers is, in the main, that of construction, in the broad sense of that word, and includes the excavation of foundations, area paving, the placing and fixing of framework and reinforcing steel, concreting, backfilling and trimming. Section 60(1) of the Act provides that, subject to the Act, an award (which, by definition, includes an order) of the Commission is final and conclusive and shall not be challenged, appealed against, reviewed, quashed or called in question in any court. The sub-section expressly provides that such an award "is not subject to prohibition, mandamus or injunction in any court on any account". Such a statutory provision is effective to exclude any general judicial review of the proceedings of the Commission. It is not, however, effective to preclude this Court from exercising the powers directly conferred upon it by s. 75(v) of the Constitution. The members of the Commission are officers of the Commonwealth and, if the Commission purports to exceed its powers or fails to perform its lawful functions, they are, as such officers, subject to the jurisdiction which the Constitution confers on this Court in all matters in which a writ of prohibition or mandamus is sought against an officer or officers of the Commonwealth (see R. v. Hickman; Ex parte Fox and Clinton [31] ). 1. (1945) 70 C.L.R. 598, at pp. 606, 610, 611, 614, 620-621. Section 142A(1) of the Act provides: The Commission may, on the application of an organization, an employer or the Minister or the Bureau, if it thinks it in the public interest to do so, make an order providing that an organization of employees shall have the right to represent, in respect of all or some industrial interests under this Act, a class or group of employees who are eligible for membership of the organization, either generally or subject to such limitations as it may specify, to the exclusion of another organization or organizations and may make such orders as it thinks necessary in consequence of such an order. The Commission's power to make an order, under s. 142A(1), that an organization of employees shall have the right to represent, in respect of all or some industrial interests under the Act, a class or group of employees is dependent upon the existence of a jurisdictional fact, namely, that the employees of the particular class or group are eligible for membership of the relevant organization. The section does not make the Commission's satisfaction as to the existence of that fact, as distinct from its actual existence, the prerequisite of the power to make an order in respect of the particular class or group of employees. Nor does the Act purport to entrust to the Commission the power authoritatively to determine the eligibility of an individual employee or a group or class of employees for membership of the relevant organization. In a context where eligibility and entitlement to become or to remain a member of a registered organization of employees to no small extent correspond (see s. 144(1) and (2) of the Act), the question of eligibility can be of fundamental importance in determining the rights and defining the legitimate aspirations of the individual employee or of a group or class of employees. The power authoritatively to decide that question is assigned by the Act to the Federal Court to be exercised as part of the judicial power of the Commonwealth (see s. 144(5), (5A) and (6) of the Act). In these circumstances, the provisions of s. 60(1) do not operate to confer any conclusive or quasi-conclusive character on the Commission's finding or opinion on the preliminary question whether the employees in respect of whose representation an order is sought are eligible for membership of the particular organization. In that regard, the position is similar to that which was under consideration in Hickman where, in referring to a Local Reference Board whose powers under the National Security (Coal Mining Industry Employment) Regulations were confined within the "Coal Mining Industry" but whose "awards or orders" were "binding on the parties" (reg. 9) and given a degree of finality and immunity from review in terms corresponding to those found in s. 60(1) (reg. 17), Dixon J. said [32] : Now, I think that it is plain that the Coal Mining Industry Employment Regulations do not mean to give either to the Central Reference Board or to the Local Reference Board any power whatever to determine the ambit of the expression "coal mining industry" or the extent of their own jurisdiction as governed by that expression. It would be unconstitutional for the Regulations to attempt to give to either Board any judicial power, and, although that is not a decisive consideration, it is a guide to the real meaning of such provisions as reg. 8 and reg. 14. On the face of those regulations it is clear enough that the words "in the coal mining industry" are words of final limitation upon the powers, duties and functions of the Boards. I therefore think that the orders under consideration undertake to decide a matter the determination or control of which is completely outside the authority of a Local Board. I do not mean to say that the Board may not, for the purpose of determining its own action, "decide" in the sense of forming an opinion upon the meaning and application of the words "coal mining industry". It must make up its mind whether this or that particular function on the borders of the coal mining industry does or does not fall within the conception. But it is not able to make a decision binding on the parties within the meaning of reg. 9, because that is the very matter which governs the extent of the operation of reg. 9, among other regulations. 1. (1945) 70 C.L.R., at p. 618. It follows that a purported order by the Commission involving representation by an organization of a class or group of employees who are not eligible for membership of that organization is beyond the powers of the Commission and liable to be corrected by this Court by writ of prohibition. Likewise, a refusal by the Commission to make an order under s. 142A(1) in favour of an applicant organization on the ground that it lacks jurisdiction to make the order sought for the reason that the relevant employees are not eligible for membership of that organization when, in truth, they are, constitutes a failure by the Commission to perform its functions in accordance with law and is liable to be corrected by this Court by writ of mandamus. The Commission must, of course, in dealing with an application for an order under s. 142A(1), make up its mind on the preliminary question whether the class or group of employees in respect of whose representation an order is sought are eligible for membership of the particular organization. Particularly where questions of industrial practice and the usage of words in industrial circles are involved, it is permissible and proper for this Court to give weight to the opinion of the Commission on that preliminary question of jurisdictional fact. It is not however, in the case of a tribunal such as the Commission which is not and cannot be invested with the judicial power of the Commonwealth, open to the Court to abrogate both its own jurisdiction and the constitutional rights of the citizen by treating the Commission's own decision on jurisdictional fact as being prima facie conclusive. It is, of course, undesirable that, in ordinary circumstances, this Court should be required to deal as a court of first instance with applications such as the present. That is not however something for which the present applicant can be blamed. It is the result of a failure by the Parliament to provide an alternative by, for example, making provision enabling a party to proceedings before the Commission to institute proceedings in an intermediate court. In the present case, the A.W.U. seeks a writ of mandamus directing the Commission to deal with the A.W.U.'s application for an order under s. 142A(1) that it be given exclusive representation of the relevant workers. The ground of the application is that the Commission has refused to consider whether an order to that effect in the A.W.U.'s favour should be made by reason of a mistaken conclusion that the relevant workers are not eligible for membership of the A.W.U. If, as the A.W.U. claims, the relevant workers are eligible to become members of it, it is plain that the Commission has wrongly concluded that it lacks power to make the order which the A.W.U. seeks and, as a result of that wrongful conclusion, has failed to consider the merits of the A.W.U.'s application. If that be the case, the A.W.U. is entitled to the issue of a writ of mandamus directing the Commission to deal with its application according to law. In addition to mandamus, the A.W.U. seeks an order prohibiting the Commission from acting on its announced decision to make an order, under s. 142A(1), granting to the B.L.F. "the exclusive right of representation" of the relevant workers. Quite apart from any entitlement to such a writ as ancillary relief to a writ of mandamus, the A.W.U. asserts an independent right to a writ of prohibition on the ground that some or all of the employees concerned are not eligible for membership of the B.L.F. If that independent ground be made good, it will follow that the order which the Commission proposes to make in favour of the B.L.F. would be ultra vires and that, subject to any question as to its standing, the A.W.U. is entitled to the writ of prohibition which it seeks. As was pointed out in the majority judgment in Reg. v. Williams; Ex parte Australian Building Construction Employees' and Builders Labourers' Federation [33] ("the Metal Structures Cases"), it is permissible, in construing the eligibility provisions of a registered organization of employees, to pay regard to any common understanding, among people concerned with relevant industries and particularly with industrial matters, of the ordinary application of the words used and to take account of evidence of that common understanding furnished by the previous use of the words in the relevant organization's rules and in statutory provisions, decisions, determinations, awards, reports and other papers concerned with the relevant industry or industries. In those respects, the question of the proper construction of particular words in the eligibility provisions of a registered organization may involve reference to and the determination of questions of fact. A decision by the Commission on the construction of words in the eligibility provisions of a registered organization will be given particular weight in this Court where such questions of fact and usage have been involved. The ultimate conclusion as to the legal effect of the words used in the eligibility provisions of a registered organization is, nonetheless, a conclusion on a question of law and, as was also pointed out in the Metal Structures Cases, where this Court has ruled upon the construction and scope of the eligibility provisions of a particular registered organization, it will, for the reasons there given, be more than ordinarily reluctant, in a subsequent case involving the construction and scope of those provisions, to depart from its previous decision or to disregard views expressed in considered comments made in reaching that decision. 1. Ante, p. 402. In Reg. v. Moore; Ex parte Federated Miscellaneous Workers' Union of Australia [34] ("the Uranium Mining Case"), the Court was concerned to determine the proper connotation, in the context of the eligibility provisions of the A.W.U., of the reference to every bona fide worker "engaged in manual or mental labour in or in connexion with [any of the following industries or callings, namely:] metalliferous mining ". Those same words in that same context are the words whose connotation is in issue in the present case. The workers in the Uranium Mining Case were or would be engaged, as employees of various project consulting engineers, in the construction of "the mining installations and associated works" at various sites in the Northern Territory. At each mining site there were to "be constructed extensive works including a concentrator, tailings dam, retention pond, administration buildings, explosives magazine and housing areas. In addition, at Jabiru and Jabiluka an acid plant and power-house are to be constructed. Roadworks, water and sewerage works and wharves with loading facilities will be constructed and a township will need to be built" [35] . It was held by a unanimous court that all the relevant workers were engaged in the metalliferous mining industry for the purposes of the A.W.U.'s eligibility provisions and were eligible for membership of the A.W.U. 1. (1978) 140 C.L.R. 470. 2. (1978) 140 C.L.R., at p. 476. For present purposes, the actual decision in the Uranium Mining Case is plainly relevant. Even more important however is the wide connotation which the members of the Court gave to the reference to the industry of "metalliferous mining" in the context of the A.W.U.'s eligibility provisions. The main judgments were delivered by Jacobs and Aickin JJ. Barwick C.J. expressed his agreement with the judgment of Aickin J. Stephen J. expressed his agreement with the judgment of Jacobs J., while Gibbs J. expressed his general agreement with the reasons given by each of Jacobs and Aickin JJ. Examination of the judgments of Jacobs and Aickin JJ. discloses that there lay, at the heart of the reasoning contained in each judgment, the conclusion that the industry of "metalliferous mining", in the context of the A.W.U.'s eligibility provisions, encompassed not only the actual process of mining and treating minerals but also the preliminary construction of mine, treatment plant and associated facilities before the extraction of minerals commenced. Thus, the following passage is central to the judgment of Jacobs J. [36] : It is abundantly clear that the four mining companies each wish to have constructed a mine or mines with all ancillary works. It is equally clear that the other companies propose to engage in the work of constructing the mines and all their ancillary works. Nothing could be more closely related to metalliferous mining than constructing or having constructed a metalliferous mine and its ancillary works. It is an integral part of the mining operation. See Re Federated Liquor and Allied Industries Employees' Union of Australia; Ex parte Australian Workers' Union, per Barwick C.J. [37] . The facts in the lastmentioned case were quite different. Catering and cleaning services were far removed from any concept of metalliferous mining which was the relevant industry in that case. The decision does not assist the present applicant. The argument of the applicant has the extraordinary result that the metalliferous mines and their ancillary works would be constructed without anybody engaged in that construction being engaged on work in or in connexion with metalliferous mining. It seems to me that the proposition has only to be stated in order that it may be seen how untenable the argument is. Construction work cannot be looked at apart from what is being constructed. The connexion is so close as to be inseparable. The mine owner is engaged in or in connexion with the industry of metalliferous mining when it has its metalliferous mining installations and associated works constructed. The constructor is engaged in work in connexion with metalliferous mining when it constructs the mining installations and associated works (emphasis added). To the same effect, and likewise central to his judgment, is the following passage from the judgment of Aickin J. [38] : the activities of the project engineers in the present case cannot, in my opinion, be said to be "quite distinct and separate from that of the mining companies engaged in metalliferous mining". Here what they are doing is itself part of the business of metalliferous mining, and at the very least it is " in connexion with " that industry. It is, I think, equally clear that there is no "separateness of establishments" in the sense referred to in the passage quoted because on the facts here in question the "establishment" of each project engineer is in truth that of the mining company for the purpose of carrying out the latter company's mining operations during both the construction and the mining stages. Applying the other test quoted, the substantial character of the industrial enterprise in which the project engineers and their employees will be engaged will be in the metalliferous mining industry, notwithstanding that all, or some, of it may properly be called construction work (emphasis again added). 1. (1978) 140 C.L.R., at p. 477. 2. (1976) 51 A.L.J.R. 266, at p. 268. 3. (1978) 140 C.L.R., at p. 485. In their joint decision in the Commission, Alley J. and Mr. Commissioner Johnson, with whose reasons on this point the third member (Coldham J.) indicated his general agreement, referred in detail to both the Uranium Mining Case and to the prior decision of this Court in Reg. v. Federated Liquor and Allied Industries Employees' Union of Australia; Ex parte Australian Workers' Union [39] ("the Poon Bros. Case"). In the latter case, employees of sub-contractors engaged by a mine management company to provide catering, cleaning, laundry, housekeeping and garbage services for and in respect of its mining employees and their dependants and the accommodation provided for them in the mining township of Newman in Western Australia were held not to be workers in or in connexion with the metalliferous mining industry within the meaning of those words in the A.W.U.'s eligibility provisions. Alley J. and Mr. Commissioner Johnson concluded that the decision in the Poon Bros. Case, was more in point as regards the relevant workers in the present case than was the decision in the Uranium Mining Case. With due respect, we are quite unable to agree that that is so. 1. (1976) 51 A.L.J.R. 266; 11 A.L.R. 449. In the Poon Bros. Case, the workers involved were not performing work which constituted, of its nature, part of the industry of metalliferous mining. If they had been actually employed by the mining companies it may nonetheless have been the case that they were workers employed in connexion with that industry. The sub-contractors which employed them were not, however, themselves engaged in the metalliferous mining industry. They were engaged in supplying the particular services which they supplied. In those circumstances, the relevant employees in the Poon Bros. Case were plainly employed in supplying those services and not in the mining industry. On the other hand, once it is accepted, as the Uranium Mining Case establishes, that the words metalliferous mining industry as used in the A.W.U.'s eligibility clause encompass not only the extraction and treatment of the mineral but the preliminary construction of mine, refinery and associated facilities, it is plain that the workers in the present case are themselves performing work in or in connexion with that industry and that they are employed by sub-contractors who are, in so far as the work of those workers is concerned, themselves engaged in that industry. The application of the considered comments of Jacobs and Aickin JJ., set out above, to the circumstances of the present case leads, in our view, to the conclusion that all of the relevant workers are eligible to become members of the A.W.U. in that they are, for the purposes of the A.W.U.'s eligibility provisions, workers "engaged in manual or mental labour in or in connection with" the metalliferous mining industry. For the reasons to which we have already referred, we are of the view that those considered comments of Jacobs and Aickin JJ. should be followed and applied in the present case. It follows that the Commission was in error in its conclusion that it lacked power to make an order for representation pursuant to s. 142A(1) in the A.W.U.'s favour in respect of the relevant workers. The order which the Commission has indicated that it proposes to make in favour of the B.L.F. would give to that organization "the exclusive right of representation of employees in the disputed areas at Worsley". The Commission reached its decision that it would make such an order on the mistaken premise that the relevant workers are not eligible to become members of the A.W.U. Such an order granting the "exclusive" right of representation would, while it stood, preclude the Commission making any order for representation of those workers in pursuance of the application which the A.W.U. is entitled to have the Commission deal with in accordance with law. In the circumstances, the A.W.U. is entitled both to a writ of mandamus requiring the Commission to consider in accordance with law whether it thinks it is in the public interest that an order under s. 142A(1) in respect of the relevant workers be made in the A.W.U.'s favour and, by way of ancillary relief, to a writ of prohibition preventing the Commission acting on its decision, made on the mistaken basis that the relevant workers are not eligible to become members of the A.W.U., that an order for exclusive representation should be made in favour of the B.L.F. As has been said, the A.W.U. submitted that it was entitled to an order of prohibition on the independent ground that the Commission was in error in concluding that all of the relevant workers are eligible to become members of the B.L.F. If some of those workers are not eligible to become members of the B.L.F., an order giving the B.L.F. the exclusive right to represent them would be beyond the powers conferred upon the Commission by s. 142A(1). While it may be strictly unnecessary to determine that question, the conclusion that the Commission is required generally to re-consider what order or orders should be made as regards representation of the relevant workers, makes it desirable that we indicate the view which we have formed on it. The conclusion that the relevant workers are eligible to become members of the A.W.U. does not, of course, involve any presumption or implication that they are not also eligible to become members of the B.L.F. Their eligibility to become members of the B.L.F. falls to be determined by reference to the Rules of that organization. The industry in or in connexion with which the B.L.F. is registered is defined by its rules (r. 4a) as "the Building Industry and the Industry of the operation of concrete batching plants". The B.L.F.'s eligibility provisions are contained in r. 4 of its Rules and are as follows: The Federation shall consist of an unlimited number of persons employed or usually employed as Builders' Labourers throughout Australia on or about any building or assisting any bricklayer, mason, plasterer, carpenter, plumber or any tradesmen engaged in building operations, or employed on any making or contracting job in wood, stone, brick, concrete, iron or steel, or combination of these or other materials incidental to building construction, and any labourer engaged in the construction, repair, demolition or removal of buildings, or as scaffolder, rigger, gear hand, gantry hand or crane hand or as dogman, or as drainer on all building contracts, and any labourer excavating ground for foundations and basements of buildings, or levelling ground on a proposed building site, or doing concrete work, tar paving or asphalt work, or mortar or concrete mixing in connection with, or incidental to the foregoing operations and employees (other than motor truck drivers and clerks) engaged in the operation of concrete batching plants (except in the State of New South Wales) where such plants are used principally for the production of concrete for supply to building construction operations together with such other persons whether employees in the industry or not, as have been appointed officers of the Federation and admitted as members thereof. In construing the B.L.F.'s eligibility provisions, the members of the Commission placed particular reliance on the wide meaning which a majority of this Court had given to the phrase "building operations" in the context of the eligibility rule of the Federated Ironworkers' Association of Australia ("the F.I.A.") in Reg. v. Marks; Ex parte Australian Building Construction Employees' and Builders Labourers' Federation ("the Omega Case") [40] . They concluded that a correspondingly wide meaning should be given to the words "builders", "building" and "buildings" and to the phrases "building operations", "building construction", "building contracts", "building site" and "building construction operations" in the B.L.F.'s eligibility rule. Their approach in that regard derived support from the view expressed by Murphy J. (but by no other justice) in the Omega Case that the phrase "building operations" had the same meaning in the rules of both the F.I.A. and the B.L.F. In the light of the wide meaning which the members of the Commission gave to those words and phrases, they also concluded that it was appropriate to take an overall view of the whole Worsley complex in determining whether the relevant workers are eligible to become members of the B.L.F. On that overall view, they concluded that all the construction work at Worsley — be it in respect of mine, refinery or connecting conveyor and road or in respect of a building in a conventional sense or a functional metal structure or object — comes within the ambit of the above-mentioned words and phrases. 1. (1981) 147 C.L.R. 471. Subsequent to the decision of the Commission in the present matter, the question of the scope of the B.L.F.'s eligibility provisions arose for decision in this Court in the Metal Structures Cases [41] . The majority of the Court rejected the approach which found favour with the Commission in the present case and held that, in the light of what had been said in this Court in Reg. v. Watson; Ex parte Australian Workers' Union [42] , the key terms "builders", "building", "buildings", "building operations", "building construction", "building contracts" and "building construction operations" in the context of the B.L.F.'s eligibility rule should be construed as referring to a building in the conventional sense. So construed, their connotation was different and significantly narrower than that which the Court, in the Omega Case, gave to the phrase "building operations" in the context of the F.I.A.'s eligibility rule. The Court held that, so construed, employees engaged in the construction of structures such as electricity transmission towers, steel tanks, a carbon baking furnace stack and the structural steel framework for steam raising equipment were not performing work within the connotation of the B.L.F.'s eligibility rule. 1. (1982) Ante, p. 402. 2. (1972) 128 C.L.R. 77. In the light of the majority judgment and decision in the Metal Structures Cases, it is apparent that the whole Worsley mining and refinery project cannot properly be regarded as a "building" for the purposes of the B.L.F.'s eligibility rule and that the chain of references to "building", "buildings", "building construction", "building contracts" and "building construction operations" in that rule cannot properly be construed as appropriate to refer to that whole project viewed as a single complex. It is also apparent that much of the construction work on the Worsley project cannot properly be regarded as work of the type referred to in the B.L.F.'s eligibility rule and that much of the work performed by the relevant workers falls outside the scope of the work covered by that rule. It is not suggested on behalf of the B.L.F. that all the relevant workers are eligible to join the B.L.F. either by reason of their being "usually employed" performing work of the type covered by the B.L.F.'s eligibility rule or by reason of circumstances other than their present employment at Worsley. That being the case, it is apparent that the Commission's conclusion that all the relevant workers were, by reason of the work they were performing, eligible to become members of the B.L.F. cannot be sustained. It is common ground between the parties that it is not appropriate that this Court embark on the task of determining whether members of particular classes or groups of workers at Worsley are eligible for membership of the B.L.F. Those are questions to which the Commission will, no doubt, redirect its attention before reaching any future decision to make orders in respect of the relevant workers. Writs of mandamus and prohibition should issue to require the Commission to deal with the application of the A.W.U. according to law and to prohibit the enforcement of, and further proceedings upon, the decision of the Commission to make an order under s. 142A(1) granting the exclusive right of representation of the relevant workers to the B.L.F. The application for a writ of certiorari was not pursued.