Some of today’s press coverage of the judgment in Miller, accusing judges of acting undemocratically, is deplorable. It is entirely right and proper that the Court should determine the legal extent of executive authority. That is an axiomatic judicial function in a democracy founded on the rule of law. But what of the content of the decision?

The judgment is striking in its muscularity. The Court considered the Government case to be so weak that it judged it untenable before even considering the claimant’s arguments in detail. The Government’s case, said the Court, was ‘flawed’ at a ‘basic level’. Reading the judgment, one might be forgiven for thinking that the Government had advanced a heterodox argument of outlandish proportions. In fact, it was simply asserting that it could use a prerogative power to begin negotiations on the international plane. None of this is to deny the subtlety of the issues to which that contention gives rise concerning the relationship between EU and domestic law, and the role played by the European Communities Act 1972 (‘ECA’) in mediating that relationship. But as John Finnis has shown, the Government’s position is far from unarguable.

 Once the Divisional Court had accepted – contrary to Finnis’s view – that EU law rights are to be considered domestic statutory rights enacted by Parliament, its focus inevitably shifted to the question whether the ECA was to be read as having displaced the Government’s ability to use the prerogative to begin the art. 50 process. In concluding that the ECA had indeed produced such an effect, the Court engaged in a highly creative process of statutory interpretation that involved relying upon the ECA’s status as a ‘constitutional statute’; treating the Act’s ‘constitutional status’ as evidence of Parliament’s intention – a view that is in tension with Laws LJ’s analysis in Thoburn; invoking certain ‘background constitutional principles’ that are relevant to statutory interpretation; and asserting that those principles are particularly relevant to the construction of constitutional statutes.

My point, in this short comment, is not to assess the correctness of the court’s conclusion on this matter. Rather, it is to observe that that conclusion – and the reasoning on which it is based – is highly contestable. Perhaps, therefore, the most surprising aspect of Miller is that the confident certainty of the terms in which the judgment is framed obscures almost entirely the complexity and contestability of the questions to which it gives rise, concerning the selection, content and interaction of the constitutional principles that form the prism through which the ECA falls to be examined.

Mark Elliott is Professor of Public Law at the University of Cambridge.

Click here for further analysis of the Miller case.