Case Comment: R (on the application of Miller) v Prime Minister; Cherry and others v Advocate General for Scotland  UKSC 41
Dr Richard Bowyer
The Supreme Court heard an appeal from the High Court of England & Wales and the Inner House of the Court of Session (Scotland) on the legality of the Prime Minister’s advice to HM The Queen to prorogue Parliament commencing on a date between 9th-12th September and lasting until 14th October 2019. The Inner House ruled that the matter was justiciable, and that the advice was unlawful because it was motivated by the improper (unlawful) purpose of ‘stymying’ Parliament’s role in holding the government to account and/or legislating to control the process by which the UK leaves the EU. The High Court ruled that the matter was not justiciable – i.e. not suitable for determination by a court. The Supreme Court unanimously dismissed the Government’s appeal from the Inner House and allowed Gina Miller’s appeal from the High Court: the matter was justiciable and the Prime Minister had acted unlawfully.
“[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” (per Lady Hale at ).
The Supreme Court quashed the Order in Council effecting the prorogation, meaning Parliament could resume its business as if prorogation never happened. The court ruled, further, that the Bill of Rights 1688 did not restrict the court’s ability to control prorogation, since the decision to prorogue was, in essence, an executive decision rather than one pertaining to the privileges of Parliament.
The judgment is immediately striking on several fronts: there were no dissents or separate concurring speeches; the court went further than some – but not all – commentators were expecting them to go, particularly with regards to remedies, leaving no question about what should immediately happen next; and the judgment was constructed on a set of constitutional principles in the broadest sense, rather than on discrete rules of law.
The judgment also furthered a development that we have seen in judicial review over the last two decades: a culture shift in requiring executive decision-makers to justify their decisions when challenged in a court of law. The Government seemed to offer no justification for their decision to prorogue, relying instead on the supposed non-justiciability of this decision pregnant with political ramifications. Whereas judicial review once placed considerable burden on the claimant to prove pretty much everything, defendants are now increasingly required to justify their decisions: in ‘anxious scrutiny’ variant Wednesbury review; in cases of proportionality review; and in cases involving a legitimate expectation of a substantive benefit. We can add to that list: review of executive action which ‘impedes or frustrates the operation of the relevant [constitutional] principle’ (at ).
Constitutional principle is indeed what survives and thrives in the Supreme Court ruling: the principle that Parliament is sovereign, and the principle that the executive is politically accountable to Parliament for its policy and decision-making. To suspend or prorogue Parliament for an unusual length of time without justification is a challenge to both of these principles and our whole system of representative democracy, for it prevents Parliament from sitting at all, as lawmaker or scrutineer. The court sought to protect these principles by identifying the constitutionally correct legal framework through which the court could legitimately speak. Rather than second-guessing or inferring (or imputing) the intentions of the prime minister, the court instead looked to define the limit or scope of the prerogative to prorogue. This would be relatively straightforward for a statutory power, which would have a textual existence, but much more difficult for a prerogative power which is a construct of the common law. The court’s solution was to focus on the effectof the decision on the functioning of important constitutional principles. In this case, the impact or effect was extreme, and the justifications absent – hence unlawful.
As Lady Hale notes (at ), this appeal is without precedent and is unlikely to occur again in the future. However, this is not the first time in recent years that the Supreme Court has had to discuss the limits of the prerogative powers of the executive in the context of Brexit. In Miller No.1  UKSC 5, the Supreme Court ruled by 8-3 majority that the prerogative could not be used to trigger the legal process for leaving the EU without parliamentary authorisation, since Parliament had previously (in 1972) manifested an intention to treat EU law as an overriding source of domestic law – something which only Parliament could reverse. Again, the judgment was heavy in constitutional principle.
There was a time when constitutional principles such as parliamentary sovereignty were widely recognised but were not tools in themselves for providing judicial determinations. Typically, principle would help guide the development of rules which were then applied in the case before the court. The ‘Enrolled Bill’ rule would be a good example of this: the principle that Parliament is sovereign leads to the rule that courts should not inquire into flaws in the legislative process to invalidate Acts of Parliament. Now, following Miller (No.1 & 2), the principles themselves are the stuff of our law. How important/big is the principle? What effect is made upon the principle? What justifications are there for limiting the principle on this occasion? If the Supreme Court has to argue from principle and not law, we place too much responsibility in the hands of judges to protect our way of life and system of government.
The Supreme Court made the right call in this case, in the absence of other tools at its disposal. But a more defined separation of powers, or a more codified constitutional settlement, would make this sort of eleventh-hour judgment unnecessary. Our constitution is being seriously tested by Brexit. The world is flirting with populism. A rules-based constitution is the best protection of our democracy, yet it is something that is missing from our legal system currently. For the sake of our cherished constitutional principles, where are the rules?