To readers of this blog, the circumstances in which 11 Justices of the United Kingdom Supreme Court unanimously invalidated the prorogation of the UK Parliament are likely notorious (if not, see the UKSC’s excellent summary). The Prime Minister had tendered advice to the Queen that Parliament should be prorogued from a date between 9-12 September until 14 October. The date on which the United Kingdom is presently scheduled to leave the European Union is 31 October. On 24 September 2019, the UKSC held that the Prime Minister’s advice to the Queen was unlawful as it was outside the Prime Minister’s powers to give it. This unlawfulness negated the Order in Council that was consequent upon it, and the prorogation that was consequent upon the Order in Council. To put it beyond doubt, the UKSC stated that ‘Parliament has not been prorogued’: .
The government had argued that the advice to the Queen was not justiciable as it was inherently political and there were no legal standards against which to judge its lawfulness. The UKSC held that what was really in issue was the existence of limits on the prerogative power to prorogue Parliament and that it was the function of the judiciary to examine the existence and extent (that is, the limits) of a prerogative power: . In a passage that has, it seems, come to overshadow the rest of the judgment, the UKSC set out at  the relevant limit upon the power to prorogue as follows:
a decision to prorogue Parliament (or to advise the monarch to prorogue Parliament) will be unlawful if the prorogation has the effect of frustrating or preventing, without reasonable justification, the ability of Parliament to carry out its constitutional functions as a legislature and as the body responsible for the supervision of the executive.
Others have written about the UKSC’s use and extension of the principles of parliamentary sovereignty and parliamentary accountability (a user-friendly euphemism for responsible government) and what the judgment might mean for any reserve power of the Queen to ignore advice. Many have advanced arguments for and against the UKSC’s intervention. Dr Joe McIntyre of the University of South Australia has helpfully collected the existing commentary on his Twitter feed.
My focus is on the relevance for Australian public law of the UKSC’s analysis of when an exercise of prerogative power will raise a justiciable issue, specifically the analysis at -. The UKSC there identified two different issues. The first was whether a prerogative power exists and, if it does exist, its extent. The second was whether a power’s exercise within its legal limits is amenable to judicial review. In this regard, the decision is entirely consistent with the Australian approach to the distinction between jurisdictional error and non-jurisdictional error, a distinction long-accepted to have been abandoned in the UK. Of course, the judgment doesn’t mention the words “jurisdictional error” – that might have been considered almost heretical in light of comments made by the UKSC in Cart, eg at - (Baroness Hale JSC), - (Lord Dyson JSC). But it is very clear that the Court’s position is that it is the role of a court to establish whether a limit on power has been breached.
In Australia, it is now well-accepted (by the courts at least) that the jurisdiction to conduct judicial review of executive action for jurisdictional error is a constitutionally entrenched aspect of the jurisdiction of the High Court and the State Supreme Courts. Review for jurisdictional error is all about the identification and enforcement of a power’s limits, as the High Court has made clear in cases such as Aala at ,  (Hayne J) andKirk - (French CJ, Gummow, Hayne, Crennan, Kiefel and Bell JJ). As I have noted elsewhere, the focus on identification and enforcement of limits, rather than legislative intention as to the consequences of an error, gives the concept of jurisdictional error utility in relation to non-statutory executive action as well as action authorised by statute. This focus on limits has meant that the ‘administrative law question’ of whether a ground of review has been established in respect of a purported exercise of power has been subsumed in the ‘constitutional law question’ of whether power existed. Standards of lawful government decision-making applicable to the exercise of a power inform the limits of that power, such that a departure from those standards renders the consequent action invalid. How to identify those standards where the power being exercised is not derived from a statute is a question beyond the scope of this blog post. (The question is addressed, in a manner not dissimilar to the UKSC’s analysis at -,  of Miller 2/Cherry, in my chapter in a forthcoming collection edited by Dr Janina Boughey and Dr Lisa Burton Crawford, Interpreting Executive Power.) The point to draw out here is that the crucial question for an Australian court conducting judicial review for jurisdictional error is now: did the decision-maker have the power to do what he or she did in the way that he or she did it? When the question is framed in that way, it is clear that court’s focus is on the identification of limits on power. The court’s focus is on ‘whether a … power exists, and if it does exist, its extent’: Miller 2/Cherry at .
Thus, the UKSC’s first issue in relation to justiciability can be seen to be the same as the inquiry of an Australian court conducting judicial review for jurisdictional error. What, then, is the relationship between Australian judicial review principles and the UKSC’s second justiciability issue: whether, where a power exists and has been exercised within its limits, the exercise of power is open to legal challenge on some other basis. When a power has been exercised within its limits but another error is alleged, that error is known in Australia as a non-jurisdictional error. Without using jurisdictional error terminology, the UKSC has set up a distinction between jurisdictional and non-jurisdictional errors and the different roles of a court in respect of each. This is entirely consistent with the approach of Australian courts since the High Court’s insistence of the maintenance of the distinction in Craig v SA.
Having made this (entirely familiar, to Australian eyes) distinction, the analysis of the UKSC then took a somewhat surprising turn. The UKSC stated that questions of justiciability, in the sense of the appropriateness of a dispute for resolution by a court, only arise in relation to the second issue; that is, where a non-jurisdictional error is alleged: . The Court relegated the central holding of the House of Lords in the seminal CCSU case, that the amenability of an exercise of prerogative power to judicial review would depend on the nature and subject matter of the particular prerogative power being exercised, to being of relevance only where a power has been exercised within its limits and another error is alleged: . This is a caveat on the CCSU principle that, to my knowledge, has not been imposed before. It was in this regard, the Court stated, that Lord Roskill in CCSU at 418 referred to the dissolution of Parliament as non-justiciable. On this reasoning, if a dissolution was within the limits of the power to dissolve Parliament, that dissolution would not be amenable to judicial review. If there was a question about the limits of the power to dissolve Parliament, this question would be entirely justiciable due to questions as to the limits of power being, ‘by definition questions of law. Under the separation of powers, it is the function of courts to determine them’: .
Despite its apparent novelty in terms of the effect of the decision in CCSU, this analysis is also entirely consonant with Australian judicial review principles due to their reliance, to a large extent, on jurisdictional error. The identification of limits on power and whether they have been breached go to the establishment of jurisdictional error. They are matters in respect of which some courts have a constitutionally-entrenched jurisdiction to conduct judicial review. An applicant for judicial review will, therefore, always get at least as far as being able to make arguments that the limits of a power were breached by its purported exercise in particular circumstances. An applicant will be able to argue, for example, as was argued in Miller 2/Cherry, that a particular activating purpose meant that a power’s limits had been breached. In such a case, it would be for the court to determine whether the limits of a power are informed by the purpose for which it is exercised. (It was not necessary for the UKSC to determine this question in Miller 2/Cherry:-). If the court decides that no limit of the relevant power has been breached, the question becomes the review available in respect of non-jurisdictional error. In the United Kingdom, the inquiry turns to the nature and subject matter of the power exercised and the courts would, it seems, extend great latitude to the judgement of the relevant executive officials: see , . In Australia, depending on the court and the source of jurisdiction that has been invoked, any claim in respect of what must be a non-jurisdictional error may not be amenable to review because the court may not have jurisdiction. But whether a limit on power has been breached is always a justiciable question.
What this demonstrates is that, as I and others have said elsewhere, there is not as much disunity between Australian and United Kingdom judicial review principles as we may have thought. Although the British courts eschew jurisdictional error terminology, the same legal errors that warrant judicial intervention there may be considered to be jurisdictional errors in Australia. Thus, in both jurisdictions, a denial of procedural fairness or an unreasonable exercise of discretion, for example, may warrant the invalidation of the consequent decision in an appropriate case.
Of course, no discussion of jurisdictional error in Australia these days is complete without a discussion of materiality. Has the UKSC unwittingly weighed into the debate presently raging within the High Court (see Hossain and SZMTA)as to whether an error can only be jurisdictional if it is material (favoured by, it seems, Kiefel CJ, Bell, Gageler, Keane and Edelman JJ) or whether materiality is relevant only to the discretion to refuse relief (Nettle and Gordon JJ)? ‘Material’, in this context, has been held to mean that the commission of the error deprived an applicant of the possibility of a successful outcome: SZMTA  (Bell, Gageler and Keane JJ).
The relevant passage of Miller 2/Cherry in this regard is at -. At , the UKSC states that a prorogation will be ‘unlawful’ if it has a certain effect, and that the court will intervene if the effect is sufficiently serious to justify such an exceptional course. By ‘intervene’ here, the Court must mean the granting of a judicial remedy. It can’t mean intervention by way of conducting judicial review, because it is by conducting judicial review that the court ascertains whether the act had the requisite effect.
This might suggest that the UKSC is on the Nettle/Gordon JJ side of the debate: first establish whether the limit was breached such as to render the action unlawful, then determine whether the effect of the breach was material. This analysis is fortified at , where the Court states that, if the relevant actor has not remained within the legal limits of the power, the final question for the court will be ‘whether the consequences are sufficiently serious to call for the court’s intervention’. The Court seems to anticipate that there can be a breach of the limits of a power (a jurisdictional error) without the breach being sufficiently serious as to warrant the granting of a remedy.
On the other hand, it could be argued that, reading the reasons as a whole, the Court is saying that only if the effect is sufficiently serious will a limit on the prorogation power have been breached. That is, that the effect of an error must be material before a limit on power will have been breached. It is the seriousness of the effect of a prorogation that dictates what would constitute ‘reasonable justification’ for the prorogation. For example, a prorogation of only 4 days would still frustrate or prevent Parliament’s ability to perform its constitutional functions but it is not a serious effect, so the justification required will be minimal, likely leading to no limit of the power being breached: see , . But, in this situation, there is no breach of limits the materiality of which needs to be assessed to determine whether invalidation follows. It is not as though there is a breach of constitutional principle that is not material, and for that reason the action stands as valid. Rather, there is no breach of constitutional principle to begin with.
A number of points should be borne in mind before either side of the materiality debate claims Miller 2/Cherry as vindication.
First, the measure of seriousness of the effect in that case was not whether it would have changed the advice of the Prime Minister but the impact that the action would have on fundamental constitutional principles. There is no necessary symmetry between a sufficiently serious effect on a principle and an error that could have led to a different decision.
Secondly, the requirement of materiality to establish jurisdictional error has been justified on the basis that the legislature does not intend for every breach of a requirement to invalidate the consequent decision. There being, of course, no legislative intention to speak of in the construction of the limits of a non-statutory power, any materiality requirement must seek an alternative justification. As I explain in relation to other principles in my forthcoming chapter, this is not to say that materiality can play no role in the ascertainment of limits on a non-statutory power. The question is always one of the proper construction of the power and its limits, derived from common law principles. It is possible that a threshold of materiality (whether reflective of seriousness of effect, a denied opportunity for a successful outcome or another test) is implicit in an applicable common law principle. An example may be the need for ‘practical injustice’ before a denial of procedural fairness may constitute a jurisdictional error: Lam at - (Gleeson CJ). By assessing the lawfulness of prorogation by reference to the seriousness of the effect of the prorogation on the ability of the legislature to perform its constitutional function and the justification offered for that effect, the UKSC seems to have embedded a threshold of materiality within the common law principles from which the limit is derived. If that it so, is accords more with the view on materiality currently prevailing in the High Court than with the dissenters.
No doubt the great Australian materiality debate was the furthest thing from the minds of the members of the Supreme Court when they penned this unanimous, clear and eminently readable judgment in 4 days (including a weekend). It is therefore doubtful that anything written there is going to clinch the debate in favour of one view rather than another. But there is much in the reasoning deployed in the judgment that is familiar to its Australian readers. So much so that one might be tempted to chalk this up as a victory in the never-ending competition between Australia and England. First the Ashes, now judicial review principles. I’m sure it will make the headlines any day now.
Amanda Sapienza is a Senior Solicitor in the Crown Solicitor’s Office (NSW). She has recently completed her doctoral thesis on judicial review of non-statutory executive action in Australia. This piece was written in a personal capacity and does not necessarily reflect the views of the Crown Solicitor or the NSW government.