The UK Supreme Court recently delivered a judgment that will, I think, be of interest to those Canadian readers who have not yet heard of it. That is because the case, R (Unison) v Lord Chancellor  UKSC 51, arises out of circumstances that are fundamentally similar to those of the Supreme Court of Canada’s decision in Trial Lawyers Association of British Columbia v. British Columbia (Attorney General), 2014 SCC 59,  3 SCR 31. Trial Lawyers, which I summarized here, concerned a challenged to the fees that litigants had to pay for each day they argued their cases in the (trial) Supreme Court of British Columbia. Unison involved fees imposed on litigants who took their cases to tribunals charged with the resolution of employment law disputes. But the ways in which the courts addressed the legal issues highlights the differences both between the respective constitutional frameworks of Canada and the UK, and between the courts’ understandings of their roles within these frameworks.
In Trial Lawyers the majority addressed the constitutionality of hearing fees, concluding that, if they are set so high as to prevent people accessing superior courts, they would contravene section 96 of the Constitution Act, 1867, which had previously been held to protect the “core” jurisdiction of the courts to which it refers. While the Chief Justice’s opinion, for the majority, also addressed the principle of the Rule of Law, it invoked this principle only as additional support for its conclusions ― Justice Rothstein’s accusations to the contrary notwithstanding. Only Justice Cromwell, in his concurrence, proposed deciding the case on administrative law grounds, and would have held that since the hearing fees were imposed by delegated legislate made pursuant to a statute that preserved the common law right of access to courts, they could not validly interfere with this right. Yet interfere with it they did, and they were therefore invalid for that reason.
By contrast, Unison was decided on administrative law grounds ― and the principle of the Rule of Law was central to the UK Supreme Court’s reasoning. Having concluded that, as a matter of empirical fact (on which more below), the fees at issue deter substantial numbers of people from pursuing their claims, the Court asked itself whether “the text of” the statute pursuant to which the fees were imposed by the executive, “but also the constitutional principles which underlie the text, and the principles of statutory interpretation which give effect to those principles”  provided authority for setting the fees at their current level. The relevant principles included, in particular, “the constitutional right of access to justice: that is to say, access to the courts (and tribunals …)”,  which in turn is an aspect of the Rule of Law. They also included the idea that rights granted by a statute cannot be nullified by delegated legislation purportedly authorized by a different statute.
The Court began with what Mark Elliott, on his excellent Public Law for Everyone blog, described as
a primer — albeit a very powerful one — on what the rule of law means … . Indeed, it is difficult to escape the conclusion that the Court felt it necessary to drive home some very fundamental propositions — ones that should not really need to be driven home — because the Government’s position indicated ignorance of or contempt for them.
As part of this “primer”, the Court emphasized that
Courts exist in order to ensure that the laws made by Parliament, and the common law created by the courts themselves, are applied and enforced. … In order for the courts to perform that role, people must in principle have unimpeded access to them. Without such access, laws are liable to become a dead letter, the work done by Parliament may be rendered nugatory, and the democratic election of Members of Parliament may become a meaningless charade. That is why the courts do not merely provide a public service like any other. 
In the course of adjudicating disputes, courts both ascertain important legal principles and provides the assurance that “[p]eople and businesses … will be able to enforce their rights if they have to do so, and … that if they fail to meet their obligations, there is likely to be a remedy against them.”  For this assurance to be effective, “people and businesses” must be able to take their disputes to courts or tribunals, if need be.
Given the importance of access to courts and tribunals, “any hindrance or impediment
by the executive requires clear authorisation by Parliament”,  and the authorization will only be taken to extend so far as the achievement of its purposes requires. As Parliament did not clear empower the executive to levy fees that would prevent litigants from accessing tribunals, and as the fees at issue had precisely that effect, they must be held not to have been authorized by the statute under whose purported authority they were imposed. In addition, they “must be regarded as rendering … nugatory”  the rights which the tribunals are supposed to enforce, thought in the Court’s view this point this point overlapped with the Rule of Law one.
It is tempting for people used to constitutional frameworks where legislation can be invalidated for inconsistency with the supreme law to look down on a decision based on administrative law grounds, which can be overridden by legislation. Indeed, even prof. Elliott writes that “for all that the case represents a striking and robust reaffirmation of fundamental constitutional principles, it also hints at — or least raises questions about — the limits of those principles” ― within the UK constitutional context, that is. After all, if the UK executive insists on collecting prohibitive tribunal fees, it can (try to) get Parliament to enact them into statute, or explicitly allow fees to be set at levels that will result in impeded access. If the UK Parliament does either of these things, there can probably be no challenge to its decision within the UK’s internal legal order, subject to courts taking up the occasional musings of some judges about limits to Parliamentary sovereignty ― an unlikely, and at least arguably an undesirable prospect. (Prof. Elliott, mixing metaphors somewhat, describes as a “nuclear option”, and says that “we will cross this bridge if we ever come to it, while fervently hoping that we never do”.) It is better, we might be tempted to say, for courts to have at their disposal the more powerful weapons that an entrenched constitution, like that of Canada, can provide.
But, while there is a good deal of truth to this view, it is not the whole truth. Prof. Elliott suggests that
in some constitutional orders … administrative orders incompatible with the right of access to justice would be unlawful — because the constitution would withhold the authority to legislate in breach of such a fundamental right.
But things might not be so simple. Prof. Elliott does not say what “constitutional orders” he has in mind, but at least in the Canadian constitutional order, it is by no means clear that the constitution withholds the right to legislate in breach of the right of access to justice. In commenting on Trial Lawyers here, I said that not only does the reasoning of the majority opinion in Trial Lawyers “rest on shaky foundations” whose weaknesses are brutally exposed by Justice Rothstein’s dissent, but they “leave some important questions” ― questions about the limits of the constitutional principles that it applies ― “unanswered”. In particular, it is very doubtful that the right of access to superior courts constiutionalized in Trial Lawyers extends to provincial court and to administrative tribunals (which is to say, to the sort of decision-maker at issue in Unison!), to which section 96 of the Constitution Act, 1867, on which that decision ostensibly rests, does not apply.
The legitimacy of judicial interventions to uphold fundamental constitutional principles can be questioned not only in constitutional systems that acknowledge Parliamentary sovereignty, but also in those that allow for judicial review of legislation ― if not in principle, then in (almost) any given case. The best answer to such questions is, of course, the existence of a clear constitutional provision in which the intervention at issue can fairly be rested. In the absence of such constitutional authority, judges are apt to grasp at textual straws, and, at the risk of also mixing metaphors, we know that a house built of straw can easily be blown away. In short, the existence of an entrenched constitution does not always make for very solid decision-making.
Indeed, Unison has at least one substantial advantage over Trial Lawyers. Its discussion of the Rule of Law principle is relatively extensive and forthright. The UK Supreme Court makes no apologies about the Rule of Law being central to its decision. The majority opinion in Trial Lawyers, however, approached the Rule of Law somewhat gingerly, and insisted that it is not the main basis for its decision ― though this was not enough to mollify Justice Rothstein, who claimed that
[i]n using an unwritten principle to support expanding the ambit of s. 96 to such an extent the majority subverts the structure of the Constitution and jeopardizes the primacy of the written text. 
For my own part, I have argued here that Trial Lawyers should, and could have been decided on the basis of the Rule of Law principle ― though my argument was a version of the “no making rights nugatory” one that the Unison Court only briefly addressed. Perhaps the Supreme Court of Canada did not address it only because it was not put it by the parties. (The cases on which it rests in the Canadian context are not well known, I suspect.) Perhaps it would have found this argument unconvincing in any event. But I suspect that the Trial Lawyers majority would have hesitated to enlist this argument even if it were convinced by it, due to the sort of concern to which Justice Rothstein appealed (unpersuasively in my view). As Jeremy Waldron observed in “The Core of the Case against Judicial Review”, constitutional adjudication under an entrenched text is liable to pay more attention to the text than to fundamental principle. In my view, this is not always a bad thing ― but it is, admittedly, not always a good one either.
Before concluding, let me note another point of contrast between Trial Lawyers and Unison: their respective treatment of empirical data. The majority opinion in Trial Lawyers is a fairly abstract one, in the sense that its focus is very much on the legal issues. It only briefly alludes to the personal circumstances of the original plaintiff in the case, pointing out that she was “not an ‘impoverished’ person in the ordinary sense of the word” (which made her ineligible for an exemption from the fees at issue). In Unison, meanwhile, statistics and data-based hypothetical scenarios intended to expose the effect of the fees at issue take up an important place in the judgment. The Court reviewed in considerable detail the nature of the disputes to which the fees at issue applied, with the aim of showing that most of them involved parties of limited means seeking to recover small amounts (or, in some cases, to obtain non-pecuniary remedies), as well as the financial effects of these fees on economically vulnerable litigants. The Court linked the precipitous drop in the number of disputes heard to the deterrent effect of excessive, and rarely recoverable, fees, providing the factual underpinning for its legal reasoning. Later on, it also discussed the fees’ failure to raise much revenue, concluding that “it is clear that the fees were not set at the optimal price: the price elasticity of demand was greatly underestimated”.  In that way, Unison is similar to cases that are part of what I have been discussing here, using Kerri Froc’s label, as the “empirical turn” in Canadian constitutional law ― while Trial Lawyers was not.
Despite originating in fairly similar circumstances, then, Trial Lawyers and Unison are quite different decisions. Each has its own logic and responds to its own concerns. But it is also true that they are both parts in delivering a unified message: that of the common law courts’ endorsement, sometimes ringing and sometimes more muted, of the value of access by the citizens to the adjudication of rights claims. Beyond the differences of strictly legal issues and methods, there is a single theme: that, as a matter of political morality, a state that purports to respect and even to create rights must not prevent citizens from asserting them.