Minister for Immigration and Citizenship v Li [2013] HCA 18

HIGH COURT OF AUSTRALIA

FRENCH CJ, HAYNE, KIEFEL, BELL AND GAGELER JJ

MINISTER FOR IMMIGRATION AND CITIZENSHIP APPELLANT

AND

XIUJUAN LI & ANOR RESPONDENTS

Minister for Immigration and Citizenship v Li [2013] HCA 18 8 May 2013 B68/2012

ORDER

Appeal dismissed with costs.

On appeal from the Federal Court of Australia

Representation

J T Gleeson SC, Acting Solicitor-General of the Commonwealth with G R Kennett SC and A L Wheatley for the appellant (instructed by Clayton Utz Lawyers)

L Boccabella with W J Markwell for the first respondent (instructed by AJ Torbey & Associates)

Submitting appearance for the second respondent

Notice: This copy of the Court's Reasons for Judgment is subject to formal revision prior to publication in the Commonwealth Law Reports.

CATCHWORDS

Minister for Immigration and Citizenship v Li

Immigration – Migration Review Tribunal – Review of decisions – Visa applicant sought review by Migration Review Tribunal ("Tribunal") of decision of Minister's delegate to refuse skilled residence visa – Section 363(1)(b) of Migration Act 1958 (Cth) gives Tribunal power to adjourn review of decision – Visa applicant requested Tribunal adjourn review until the outcome of a review of her skills assessment was finalised – Whether Tribunal's refusal to adjourn was unreasonable or plainly unjust.

Words and phrases – "fair and just", "fair, just, economical, informal and quick", "jurisdictional error", "unreasonable or plainly unjust", "unreasonableness", "Wednesbury unreasonableness".

Constitution, s 75(v). Migration Act 1958 (Cth), ss 349(1), 353, 357A, 360(1), 363(1)(b).

FRENCH CJ. Introduction For the purpose of exercising its function of reviewing certain visa refusal decisions under the Migration Act 1958 (Cth) ("the Act"), the Migration Review Tribunal ("the MRT") is given a variety of powers and discretions. One such power is to adjourn the review. In this case, the MRT made a decision, on 25 January 2010, adverse to the first respondent, who had been training and obtaining work experience as a cook and had been refused a Skilled–Independent Overseas Student (Residence) (Class DD) visa. As was known to the MRT when it made its decision, the first respondent was awaiting the outcome of a requested review by Trades Recognition Australia ("TRA") of the first respondent's unsuccessful application to that authority for a skills assessment. A favourable skills assessment was a necessary condition of the grant of the kind of visa which she sought. The MRT did not accede to a request from the first respondent's migration agent to defer its determination pending TRA's decision. The case has a history dating back to the initial application for a visa on 10 February 2007. The decision of the MRT was quashed by the Federal Magistrates Court ("the FMC") on 31 August 2011 by an order in the nature of certiorari and the matter remitted to the MRT by an order in the nature of mandamus. An appeal from the decision of the FMC was dismissed by the Full Court of the Federal Court on 24 May 2012. The Minister for Immigration and Citizenship ("the Minister") now appeals, by special leave, to this Court on the basis that, contrary to the conclusions of the FMC and of the Full Court, the MRT did not act unreasonably in making its decision and did not fail to apply such requirements of procedural fairness as were imposed on it by the Act. For the reasons that follow the appeal should be dismissed. The procedural history The events leading to this appeal are discussed in detail in the reasons for judgment of the plurality. Salient features of that procedural history are: • The first respondent applied for a Skilled–Independent Overseas Student (Residence) (Class DD) visa on 10 February 2007 which required satisfaction of a "time of decision criterion" set out in cl 880.230(1) of Sched 2 to the Migration Regulations 1994 (Cth) ("the Regulations"), namely that: "A relevant assessing authority has assessed the skills of the applicant as suitable for his or her nominated skilled occupation, and no evidence has become available that the information given or used as part of the assessment of the applicant's skills is false or misleading in a material particular." The application was supported by a skills assessment made on 8 January 2007 by TRA, a relevant assessing authority. The assessment was found to be based on false information submitted to TRA by the first respondent's former migration agent and on 13 January 2009 the Minister's delegate refused the application for a visa. • The first respondent, through a new migration agent, applied to the MRT for review of the delegate's decision on 30 January 2009. The migration agent submitted a fresh application to TRA for a new skills assessment on 4 November 2009. • The MRT convened a hearing for 18 December 2009 and on 21 December 2009 wrote to the first respondent inviting comment upon allegedly untruthful answers given to departmental officers in connection with her initial application. It required a response by 18 January 2010, but advised the first respondent that she could seek an extension of time. • On 18 January 2010, the first respondent's migration agent replied to the MRT's letter of 21 December 2009 and advised that the application for a second skills assessment had been unsuccessful. The migration agent pointed out "two fundamental errors" in TRA's assessment and said that the first respondent had applied to TRA for review of its adverse decision. The migration agent requested the MRT to "forbear from making any final decision regarding her review application until the outcome of her skills assessment application is finalised." He undertook to keep the MRT informed of the progress of the application. • On 25 January 2010, without waiting for advice of the outcome of the migration agent's representations to TRA, the MRT affirmed the delegate's decision. It acknowledged the agent's last letter. It did not explain its decision to proceed to a determination beyond saying: "The Tribunal considers that the applicant has been provided with enough opportunities to present her case and is not prepared to delay any further and in any event, considers that clause 880.230 necessarily covers each and every relevant assessing authority's assessment." The FMC and Federal Court decisions The first respondent applied to the FMC for judicial review of the MRT decision primarily on the ground that the MRT had failed to accord her procedural fairness when it refused to defer making its decision until after the outcome of her agent's request for a review by TRA of her skills assessment. However, the Federal Magistrate hearing the application decided it in favour of the first respondent on the basis that "the Tribunal's decision to proceed in [the] circumstances rendered it unreasonable such as to constitute unreasonableness in the Wednesbury Corporation sense." In their joint judgment dismissing the Minister's appeal to the Full Court of the Federal Court, Greenwood and Logan JJ correctly described the review function conferred on the MRT as its "core function" and said: "The MRT is given power to adjourn proceedings from time to time ... An unreasonable refusal of an adjournment of the proceeding will not just deny a meaningful appearance to an applicant. It will mean that the MRT has not discharged its core statutory function of reviewing the decision. This failure constitutes jurisdictional error for the purposes of s 75(v) of the Constitution." (emphasis in original) Their Honours also concluded that an unreasonable refusal of an adjournment would mean that the MRT had not conducted its review function in a way which was "fair", that being a requirement of ss 353 and 357A(3) of the Act. In so concluding, they invoked observations in Minister for Immigration and Citizenship v SZGUR referring to s 353 as imposing a "requirement" on the MRT. As appears later in these reasons, their Honours seem to have taken more from that observation than it conveyed. Their Honours observed correctly that the migration agent's letter to the MRT of 18 January 2010 disclosed every reason to conclude that the second skills assessment was adverse because of error on the part of TRA. They held that "there was no countervailing consideration on the basis of which it might be concluded that the refusal to adjourn was one reasonably open to the MRT." Collier J held that the MRT had failed properly to consider the first respondent's application for an adjournment and that that failure constituted a failure to give her a proper hearing within the meaning of s 360 of the Act. Her Honour, however, did not agree that issues relevant to the adjournment could be linked to Wednesbury unreasonableness. The grounds of appeal The Minister asserted in his notice of appeal that the plurality in the Full Court had erred in holding that ss 353 and 357A(3) of the Act imposed statutory requirements capable of supporting substantive grounds of review for jurisdictional error or defined the "core function" of the MRT in such a way as to include procedural requirements additional to those imposed by Div 5 of Pt 5 of the Act. The Minister also attacked the finding that principles of procedural fairness arising under the general law applied in addition to the express statutory requirements imposed on the MRT. The Minister challenged the findings of the Full Court that the relevant standard of procedural fairness had not been met in the circumstances and that the MRT's refusal of an adjournment was a decision that no reasonable tribunal could have made. The grounds of appeal direct attention to the nature of the functions conferred by the Act on the MRT. The functions and powers of the MRT The MRT is established by Pt 6 of the Act. Part 5 of the Act provides for "review" by the MRT of a range of decisions under the Act defined as "MRT‑reviewable decisions". They include decisions of the kind in issue in this case—that is, a decision to refuse to grant a non-citizen in the migration zone, who has made an application while in the migration zone, a visa of a kind that can be granted while the non-citizen is in the migration zone. Section 348 provides that if an application for review of an MRT‑reviewable decision is properly made "the Tribunal must review the decision." It may, for the purposes of the review, "exercise all the powers and discretions that are conferred by this Act on the person who made the decision." It is well established that the reviews that both the MRT and the Refugee Review Tribunal ("the RRT") undertake (both tribunals operating under similar legislative schemes) are non-adversarial and that they involve no contradictor nor the joinder of any issue. The review function of the tribunals created by the Act is sometimes called "inquisitorial". That designation is a characterisation of their function which distinguishes it from adversarial proceedings. The word "review" "has no settled pre-determined meaning; it takes its meaning from the context in which it appears." As appears from the nature of the powers conferred on these tribunals, the review each must undertake involves a fresh consideration of the application which led to the decision under review. The review must be based on the evidence and arguments placed before the tribunal and any other relevant information which the tribunal itself obtains. Each tribunal must identify for itself the issues that arise in the application before it. It is not confined to the issues considered by the delegate. There are similarities to the kind of review provided by the Administrative Appeals Tribunal ("the AAT"), described by Brennan J in Bushell v Repatriation Commission as: "an administrative decision-maker, under a duty to arrive at the correct or preferable decision in the case before it according to the material before it." As for the AAT, so too for the MRT and the RRT, the onus of proof relevant in judicial fact-finding has no part to play in administrative proceedings. There being no party to a review adverse to the applicant, no question of prejudice to a party other than the applicant can arise when the applicant asks the MRT to adjourn a review to enable additional information to be provided to the MRT. Nor can there be any prejudice to the tribunal although it is entitled to have regard to legislative objectives including timeliness in its processes. Division 4 of Pt 5 of the Act is entitled "Exercise of Tribunal's powers". It commences with s 353, which provides: "(1) The Tribunal shall, in carrying out its functions under this Act, pursue the objective of providing a mechanism of review that is fair, just, economical, informal and quick. (2) The Tribunal, in reviewing a decision: (a) is not bound by technicalities, legal forms or rules of evidence; and (b) shall act according to substantial justice and the merits of the case." The objective set out in s 353(1) is replicated, in relation to the administration of the MRT, in s 397(2)(a), which defines one of the responsibilities of the Principal Member of the tribunal as "monitoring the operations of the Tribunal to ensure that those operations are as fair, just, economical, informal and quick as practicable". Section 420 of the Act gives the same legislative directions to the RRT as s 353 gives to the MRT. The direction in subs (1) of each provision is, as was said in SZGUR, a "requirement imposed on the Tribunal, in the discharge of its core function". That requirement is formulated in terms of broad legislative objectives which are, to some degree, "inconsistent as between themselves." They are not expressed in terms or in a context which would support a claim of jurisdictional error based on the non‑observance of any of them. That view is well supported by observations about s 420 in the judgments of this Court in Minister for Immigration and Multicultural Affairs v Eshetu. There was a focus in that case on the interaction between s 420 and the limited grounds for judicial review of Migration Act decisions in the Federal Court which were enumerated in s 476 as it then stood. Nevertheless, it was the broad facultative language of s 420 that supported the conclusion that it did not give rise to grounds for judicial review based on a failure to comply with its exhortations. Gleeson CJ and McHugh J described its function as "intended to be facultative, not restrictive" and "to free tribunals, at least to some degree, from constraints otherwise applicable to courts of law, and regarded as inappropriate to tribunals." Gaudron and Kirby JJ described s 420 as determining the general nature of review proceedings and held that there was no basis for concluding that it operated to mandate specific procedures to be observed by the RRT or the method by which it was to reach its decision. Gummow J agreed with what Lindgren J had said, particularly about s 420(1), in Sun Zhan Qui v Minister for Immigration and Ethnic Affairs. Lindgren J pointed to the difficulty of invoking a failure to comply with s 420(1) as a ground of non-performance of a requisite procedure for the purposes of s 476 of the Act. Although his analysis was based upon the interaction with s 476, it threw up the general difficulty of invoking s 420(1) and similarly s 353(1) as giving rise to grounds for judicial review. A complaint about alleged non-compliance with s 420(1) might require consideration of the RRT's staff and financial resources and its internal organisations and practices. His Honour said: "A mere conclusion that a mechanism of review in its operation in a particular case did not satisfy one or more of the epithets in [s] 420(1), would not necessarily establish that the [Tribunal] had not been pursuing the specified objective." The requirements of s 353(2) are in the same terms as those applied to the RRT by s 420(2) of the Act. The language is familiar. Its ancestry dates back to statutory directions to Courts of Requests in the 17th century to make such orders "as they shall find to stand with equity and good conscience". That statutory formula evolved and was applied to tribunals in Australia both before and after Federation. An early example was the statute re-establishing the Court of Requests in the Colony of New South Wales in 1842, which became the Small Debts Court, and was required to decide matters "in a summary way, and according to equity and good conscience". The rolled-up direction to "act according to equity, good conscience and the substantial merits of the case without regard to technicalities and legal forms" was considered by the Court of Appeal of New South Wales in Qantas Airways Ltd v Gubbins. As pointed out by Gleeson CJ and Handley JA in that case, the collocation has no fixed legal meaning independent of the statutory context in which it is found. So too, s 353(2) is to be understood in its statutory context. That context makes clear that it cannot operate to allow the MRT to act other than according to the law set out in the Act in the exercise of its function of review, including the exercise of the powers and discretions conferred upon it in aid of that function. The MRT is not excused from compliance with the criteria of lawfulness, fairness and rationality that lie at the heart of administrative justice albeit their content is found in the provisions of the Act and the corresponding regulations and, subject to the Act and those regulations, the common law. Section 353(2) shares with s 353(1) a facultative rather than restrictive purpose. The two paragraphs of s 353(2) "describe the general nature of review proceedings and require the Tribunal to operate as an administrative body with flexible procedures and not as a body with technical rules of the kind that have sometimes been adopted by quasi-judicial tribunals." Its facultative character was illustrated in Minister for Immigration and Multicultural Affairs v Bhardwaj. Gleeson CJ observed that s 353 allowed a precursor tribunal, the Immigration Review Tribunal, to reopen its own decision when it learned that the decision was based upon an administrative error. Section 353(2) does not import substantive common law requirements of procedural fairness. Nothing said in SZGUR supports such a conclusion. To the extent that the Full Court of the Federal Court treated the direction in s 353 as giving rise to grounds for judicial review, it was in error. A fortiori, no substantive operation applicable to individual review proceedings is to be attributed to s 397(2)(a) of the Act. On the other hand, nothing in s 353 is adverse to the application of the requirements of procedural fairness in the exercise of the MRT's functions. A limiting definition of their application in certain respects is to be found in s 357A. It is necessary now to consider the operation of that provision in relation to procedural fairness and whether in this case procedural fairness was denied. Procedural fairness in the MRT Division 5 of Pt 5, which deals with the conduct of reviews by the MRT, includes s 357A, which provides: "Exhaustive statement of natural justice hearing rule (1) This Division is taken to be an exhaustive statement of the requirements of the natural justice hearing rule in relation to the matters it deals with. (2) Sections 375, 375A and 376 and Division 8A, in so far as they relate to this Division, are taken to be an exhaustive statement of the requirements of the natural justice hearing rule in relation to the matters they deal with. (3) In applying this Division, the Tribunal must act in a way that is fair and just." Division 5 also requires the MRT to invite the applicant for review to appear before it and to present arguments relating to the issues arising in relation to the decision under review. The MRT is empowered, for the purpose of a review of a decision, to do a number of things including seek "any information that it considers relevant", "take evidence on oath or affirmation" and "adjourn the review from time to time". What are the "matters" with which Div 5 of Pt 5 of the Act deals? In Saeed v Minister for Immigration and Citizenship the plurality held to be "plainly correct" the approach that the words "the matters it deals with" in s 357A(1) require a search to be made of Div 5 for a provision "dealing with" a relevant "matter". Division 5 of Pt 5 deals with the submission by an applicant of "a written statement in relation to any matter of fact" and "written arguments ... arising in relation to the decision under review." Division 5 does not deal with the matter of an application by an applicant for an adjournment in order to provide additional material or, as in this case, the provision of a third party assessment the existence of which is a criterion for the grant of the visa. The common law hearing rule of procedural fairness applies to the process for making a decision to grant or refuse an adjournment in such cases and informs its legal consequences where a person is said to have been deprived by a refusal of a reasonable opportunity for a hearing. The decision of this Court in Bhardwaj pre-dated the enactment of s 357A and s 422B, which makes similar provision for RRT proceedings. Nevertheless, having regard to the proper construction of those provisions, the observation in the judgment of Gaudron and Gummow JJ that "a failure to accede to a reasonable request for an adjournment can constitute procedural unfairness" remains apposite to the proceedings of the MRT and the RRT. In written submissions filed on his behalf the Minister accepted that circumstances could be envisaged in which a refusal by the MRT to delay or adjourn its processes might result in a failure to provide procedural fairness. The Minister submitted, however, that the present case was not really about procedural fairness at all. The request for a deferral of the MRT decision was made by the first respondent "in the hope that the passage of further time would see her meet the criterion which presently she did not meet." The failure by the MRT to accede to her request to defer its decision did not deny her a proper hearing. An application for review by the MRT may require the presentation by the applicant of material demonstrating compliance with a criterion to be satisfied at the time of the MRT's decision. The relevant criterion may involve evidence of a fact in existence. That fact may be, as in this case, the formation by a third party of an opinion or assessment on a matter of fact. It requires a fine distinction to accept that procedural fairness applies to a request for an opportunity to obtain evidence of a fact and to reject its application to a request for an opportunity to obtain a statutory assessment as to the existence of a fact. A reasonable opportunity to present an applicant's case with respect to a time of decision criterion will extend to the opportunity to obtain evidence of the necessary fact or to obtain the necessary opinion or assessment. The Minister's submission drew a distinction which might be thought antithetical to the legislative direction and facultative purpose of s 353 and indeed that of s 357A(3). The MRT's approach in this case, which does not appear to have been informed by that distinction, was captured succinctly, and apparently exhaustively, by the words "the applicant has been provided with enough opportunities to present her case". It made no reference to the probability that the first respondent would be able, within a reasonable time, to secure the requisite skills assessment. The Minister submitted, against a straw-person argument not put, that there is no general obligation upon the MRT to adjourn a decision because the applicant for review "considers" that the passage of time will allow a visa criterion to be met. That was not this case. There was good reason to expect that the criterion would be met. The MRT denied the first respondent what would have been, in the circumstances, a reasonable opportunity to acquire the TRA skills assessment which was essential to her success. The first respondent's migration agent had shown the MRT that there was a proper basis for expecting a favourable outcome in response to his request for a review by TRA. That was borne out by the event. There was no practical countervailing consideration disclosed in the MRT's reasons for refusing to defer its decision. The first respondent was denied procedural fairness and that denial constituted jurisdictional error. The refusal by the MRT to defer its decision was held by Greenwood and Logan JJ in the Full Court to be "unreasonable" amounting to a failure to discharge the "core statutory function of reviewing the decision." The question of the "unreasonableness" of the MRT's decision not to adjourn the review was agitated, independently of the question of its asserted failure to accord procedural fairness to the first respondent. This aspect of the case raises the question whether the decision of the MRT was unreasonable in the sense used by Lord Greene MR in Associated Provincial Picture Houses Ltd v Wednesbury Corporation, that is to say so unreasonable that no reasonable tribunal could have made it. In approaching that question it is necessary to keep in mind the distinction between a decision-maker finding a jurisdictional fact and a decision-maker exercising a discretion. The distinction was made by Gummow A-CJ and Kiefel J in Minister for Immigration and Citizenship v SZMDS when, referring to so-called "Wednesbury unreasonableness" their Honours said: "The concern here is with abuse of power in the exercise of discretion, again on the assumption that the occasion for the exercise of discretion had arisen upon the existence of any necessary jurisdictional facts. Confusion of thought, with apprehension of intrusive interference with administrative decisions by judicial review will be avoided if the distinction between jurisdictional fact and other facts then taken into account in discretionary decision making is kept in view." (footnotes omitted) Bearing that distinction in mind, it is appropriate to turn to the general question whether the MRT's decision not to defer its determination was so unreasonable as to constitute jurisdictional error. Reasonableness Every statutory discretion, however broad, is constrained by law. As Dixon J said in Shrimpton v The Commonwealth: "[C]omplete freedom from legal control, is a quality which cannot ... be given under our Constitution to a discretion, if, as would be the case, it is capable of being exercised for purposes, or given an operation, which would or might go outside the power from which the law or regulation conferring the discretion derives its force." Every statutory discretion is confined by the subject matter, scope and purpose of the legislation under which it is conferred. Where the discretion is conferred on a judicial or administrative officer without definition of the grounds upon which it is to be exercised then: "the real object of the legislature in such cases is to leave scope for the judicial or other officer who is investigating the facts and considering the general purpose of the enactment to give effect to his view of the justice of the case." That view, however, must be reached by a process of reasoning. Every discretion has to be exercised, as Kitto J put it in R v Anderson; Ex parte Ipec-Air Pty Ltd, according to "the rules of reason". His Honour, paraphrasing Sharp v Wakefield, said: "a discretion allowed by statute to the holder of an office is intended to be exercised according to the rules of reason and justice, not according to private opinion; according to law, and not humour, and within those limits within which an honest man, competent to discharge the duties of his office, ought to confine himself". Mason J in FAI Insurances Ltd v Winneke quoted Kitto J and linked his words to the general rule "that the extent of ... discretionary power is to be ascertained by reference to the scope and purpose of the statutory enactment". As Professor Galligan wrote in 1986 in Discretionary Powers: A Legal Study of Official Discretion, the requirement that officials exercising discretion comply with the canons of rationality means, inter alia, that their decisions must be reached by reasoning which is intelligible and reasonable and directed towards and related intelligibly to the purposes of the power. Those canons also attract requirements of impartiality and "a certain continuity and consistency in making decisions." They were reflected in the powers of the English Court of Chancery to control public bodies "if they proceed to exercise their powers in an unreasonable manner; whether induced to do so from improper motives or from error of judgment." They were acknowledged in the earliest years of this Court. The rationality required by "the rules of reason" is an essential element of lawfulness in decision-making. A decision made for a purpose not authorised by statute, or by reference to considerations irrelevant to the statutory purpose or beyond its scope, or in disregard of mandatory relevant considerations, is beyond power. It falls outside the framework of rationality provided by the statute. To that framework, defined by the subject matter, scope and purpose of the statute conferring the discretion, there may be added specific requirements of a procedural or substantive character. They may be express statutory conditions or, in the case of the requirements of procedural fairness, implied conditions. Vitiating unreasonableness may be characterised in more than one way susceptible of judicial review. A decision affected by actual bias may lead to a discretion being exercised for an improper purpose or by reference to irrelevant considerations. A failure to accord, to a person to be affected by a decision, a reasonable opportunity to be heard may contravene a statutory requirement to accord such a hearing. It may also have the consequence that relevant material which the decision-maker is bound to take into account is not taken into account. In Wednesbury Corporation, Lord Greene MR observed that the word "unreasonable" in administrative law was used to encompass failure by a decision-maker to obey rules requiring proper application of the law, consideration of mandatory relevant matters and exclusion from consideration of irrelevant matters: "If he does not obey those rules, he may truly be said, and often is said, to be acting 'unreasonably'." That kind of unreasonableness may be taken to encompass unreasonableness from which an undisclosed underlying error may be inferred. Beyond unreasonableness expressive of particular error however, it is possible to say, as Lord Greene MR said, that although a decision-maker has kept within the four corners of the matters it ought to consider "they have nevertheless come to a conclusion so unreasonable that no reasonable authority could ever have come to it." In such a case the court may interfere. That limiting case can be derived from the framework of rationality imposed by the statute. As explained by Lord Greene MR, it reflects a limitation imputed to the legislature on the basis of which courts can say that parliament never intended to authorise that kind of decision. After all the requirements of administrative justice have been met in the process and reasoning leading to the point of decision in the exercise of a discretion, there is generally an area of decisional freedom. Within that area reasonable minds may reach different conclusions about the correct or preferable decision. However, the freedom thus left by the statute cannot be construed as attracting a legislative sanction to be arbitrary or capricious or to abandon common sense. A connection between vitiating unreasonableness and an implied legislative intention was made by Brennan CJ in Kruger v The Commonwealth: "[W]hen a discretionary power is statutorily conferred on a repository, the power must be exercised reasonably, for the legislature is taken to intend that the discretion be so exercised." (footnote omitted) In similar vein, Gaudron J said in Abebe v The Commonwealth, in a passage quoted by Crennan and Bell JJ in SZMDS: "[I]t is difficult to see why, if a statute which confers a decision-making power is silent on the topic of reasonableness, that statute should not be construed so that it is an essential condition of the exercise of that power that it be exercised reasonably, at least in the sense that it not be exercised in a way that no reasonable person could exercise it." The requirement of reasonableness is not a vehicle for challenging a decision on the basis that the decision-maker has given insufficient or excessive consideration to some matters or has made an evaluative judgment with which a court disagrees even though that judgment is rationally open to the decision-maker. Gleeson CJ and McHugh J made the point in Eshetu that the characterisation of somebody's reasoning as illogical or unreasonable, as an emphatic way of expressing disagreement with it, "may have no particular legal consequence." As Professor Galligan wrote: "The general point is that the canons of rational action constitute constraints on discretionary decisions, but they are in the nature of threshold constraints above which there remains room for official judgment and choice both as to substantive and procedural matters. In other words, within the bounds of such constraints, different modes of decision-making may be employed." A distinction may arguably be drawn between rationality and reasonableness on the basis that not every rational decision is reasonable. It is not necessary for present purposes to undertake a general consideration of that distinction which might be thought to invite a kind of proportionality analysis to bridge a propounded gap between the two concepts. Be that as it may, a disproportionate exercise of an administrative discretion, taking a sledgehammer to crack a nut, may be characterised as irrational and also as unreasonable simply on the basis that it exceeds what, on any view, is necessary for the purpose it serves. That approach is an application of the principles discussed above and within the limitations they would impose on curial review of administrative discretions. The decision of the MRT to proceed to its determination was not, on the face of it, informed by any consideration other than the asserted sufficiency of the opportunities provided to the first respondent to put her case. The MRT did not in terms or by implication accept or reject the substance of the reasons for a deferment put to it by the first respondent's migration agent. It did not suggest that the first respondent's request for a deferment was due to any fault on her part or on the part of her migration agent. It did not suggest that its decision was based on any balancing of the legislative objectives set out in s 353. Its decision was fatal to the first respondent's application. There was in the circumstances, including the already long history of the matter, an arbitrariness about the decision, which rendered it unreasonable in the limiting sense explained above. Conclusion For the preceding reasons the appeal should be dismissed with costs.