Aileen McHarg: The Art of Judicial Disguise

September 30, 2019

The prorogation case is undoubtedly the most challenging that the Supreme Court has had to deal with so far in its relatively short history, involving a high-stakes dispute in extremely politicised territory in which there was a real risk to the court’s authority.  It is hard not to admire the skill with which the court navigated these difficult waters, through a unanimous and crystal-clear judgment which cleverly presented its conclusion as the unproblematic consequence of centuries-old constitutional precedents, and which in its approach to remedies deftly avoided the risk of government defiance.  Given the reprehensible nature of the government’s conduct, it is also difficult not to applaud the result.

However, this should not blind us to the various argumentational moves employed by the court to disguise the novelty of its reasoning and to make the result appear more inevitable than it was.

One such move – reminiscent of Anisminic – was the reclassification of what had been understood to be a decision about the exercise of prerogative power, as a question about its scope, thus allowing the court to side-step arguments about justiciability.  As in Anisminic, while the court appeared to respect the distinction between scope and exercise of a prerogative power, accepting that the exerciseof such powers may not always be justiciable, its reasoning seems to collapse the distinction. Non-justiciability appears to be reduced to a tautology – the absence of relevant legal limits on power – rather than being an independent constraint on the availability of judicial review.

In identifying legal limits on the prorogation power, the court also employed highly creative reasoning. In the first place, it derived from the accepted legal principle of Parliamentary Sovereignty a novel duty on the government not to frustrate, not merely the expressed will of Parliament, but also the ability of Parliament to express that will.  Secondly, it was prepared to recognise – on scant authority – the principle of responsible government as a legally-enforceable principle, again deriving from the recognised duty on the courtsto respect the executive’s political accountability to Parliament a positive legal obligation on the governmentto account to Parliament, notwithstanding that this duty is largely based in convention.

Finally, in assessing whether the limits on the prorogation power had been breached, the court also chose to focus on the effects of the decision, rather than on the government’s motives.  This allowed it to present its task as an objective and routine assessment of fact, and to avoid any inflammatory accusation that the Prime Minister had been lying.  Nevertheless, the court’s evaluation of the justification for the five-week prorogation necessarily involved questions of judgment about the appropriateness and weight of the reasons offered, not merely determination of facts.  It also took the court back to reviewing the exerciseof the prorogation power, not merely its scope, where questions of justiciability could have arisen.

This, then, was a highly assertive decision by a Supreme Court taking on the mantle of guardian of the constitution.  While this is not necessarily something to be regretted, there are questions to be asked about the legitimacy of the court’s role in an uncodified constitution; about the (rather conservative) nature of the constitutional order that the court is articulating and defending through its judgments; and about the effectiveness of judicial intervention – both in terms of the extent of the contribution that the court is able to make to the resolution of the current constitutional crisis, and in terms of the political reaction that its decisions may provoke.

Aileen McHarg is Professor of Public Law and Human Rights, University of Durham

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