I recently finished work on a paper that will be published in the July 2017 issue of the Cambridge Law Journal. Entitled ‘The Supreme Court’s Judgment in Miller: In Search of Constitutional Principle’, the paper analyses the decision in R (Miller) v Secretary of State for Exiting the European Union  UKSC 5. As is well-known, the Supreme Court, in that case, held that the United Kingdom’s withdrawal from the European Union could not be initiated by the Government using prerogative power; rather, the Brexit process could be begun only with Parliament’s legislative blessing. As is equally well-known, that blessing was conferred by Parliament via the European Union (Notification of Withdrawal) Act 2017 — and, on 29 March 2017, the Prime Minister, exercising the power invested in her by that legislation, triggered the withdrawal process by giving the European Council notice of the UK’s intention to leave the EU under Article 50(2) of the Treaty on European Union.
The earlier sections of my paper are devoted to a detailed analysis of the judgment, in respect of which I make three principal arguments:
- The majority’s conclusion regarding the unavailability of the prerogative turned significantly upon its view that ‘major’ constitutional changes can be made only by legislation. I contend, however, that that notion lacks support in authority, imports into the law a novel and highly imprecise criterion by which prerogative power is delimited and rests upon normative constitutional foundations that are unarticulated and arguably absent.
- The majority held that the prerogative could not be used to initiate Brexit because the EU Treaties and EU legislation are an ‘independent source’ of domestic law. This reasoning, I argue, collapses upon scrutiny; it is either incoherent or inconsequential.
- It was argued before the Supreme Court that constitutional convention required legislation initiating withdrawal from the EU to be enacted only if the devolved legislatures consented. The Court, however, refused to determine that matter. Here, I suggest that while the Court was too quick to invoke questionable arguments of constitutional principle in order to sustain its analysis of the prerogative issue, it was too slow to pay heed to the constitutional principles implicated by the devolution issue.
The later sections of the paper examine Miller in broader constitutional perspective, by considering what it tells us about — and what its implications might be for — constitutional principle and constitutional adjudication. Here, I develop two key lines of argument:
- The case illustrates the way in which the outcome of constitutional adjudication can be fundamentally shaped by the constitutional principles that are selected to form the lens through which relevant matters are examined, and by what those principles are taken to mean. If the appearance — or actuality — of a palm-tree mode of constitutional adjudication is to be avoided, the judiciary must discharge a heavy onus by transparently identifying the constitutional principles it applies when deciding hard cases, and offering rigorous reasoning as to how such principles bite upon the pertinent legal and factual issues. That burden, I argue, is not discharged by the majority’s intellectually lackadaisical judgment.
- While Miller is easy to portray as a ‘progressive’ judgment, given its curtailment of the Government’s archaic prerogative authority, the judgment paradoxically assumes a progressive air only if the constitutional order is, in the first place, conceived of in a relatively conservative way. If the issues in Miller are viewed other than in terms of the judicial allocation of authority as between the UK’s central legislative and administrative institutions, the judgment takes on a different complexion. Among other things, it demonstrates the difficulty that orthodox principle encounters when contemporary features of the constitution — such as its newly pluralistic territorial aspect and the increasing importance of referendums — are brought into play. If, then, Miller is a victory for constitutional principle, it is victory only for a particular, and contestable, understanding of what the relevant principles are and how they interact.
A pre-publication draft of the article can be downloaded here.