The majority’s reasoning in Miller may appear to turn on the proposition that the European Communities Act 1972 (‘ECA’) introduced a new source of law in the UK (-). The majority argue that, since there is no prerogative power to change UK law (-), and hence none to effect the loss of a source of UK law (, ), serving notice under Article 50 (said to undo the effect of the ECA) cannot be accomplished using the prerogative.
The success of this argument—call it the source argument—depends in large part on how to understand a ‘source of law’, a notion not free of difficulty. The majority refer to EU law as an ‘independent’ source of UK law (, , )—an infelicitous description, since, as they also acknowledge, EU law’s effect in UK law is dependent on the ECA (). EU law is not, then, an ultimate source of UK law. But it hardly follows that it is no source at all. There is nothing odd in the idea that legal systems can introduce—through their ultimate sources of law—further, derivative legal sources. Of course, UK law gives effect to all sorts of rules which do not thereby become sources of UK law. Something more is surely needed—hence the majority’s appeal to special features of EU law as it operates in the UK: its capacity to be directly effective (), precedence over other sources of UK law (), and its being subject to authoritative rulings by the CJEU ().
While the source argument is central to how the majority see the case—Mark Elliott says it is ‘pivotal’ to their analysis—at points, they make an importantly different argument: that the prerogative cannot be used to effect ‘fundamental’ or ‘major’ changes to the UK’s constitutional arrangements (, -).
Whether or not one agrees that this proposition finds support in ‘basic concepts of constitutional law’  (if not direct authority), it at least has the attraction of sidestepping the vexed notion of a source of law. It is true that the majority treat the loss of a source of law as the constitutional change at issue. But the important point is that the fundamental constitutional change argument can stand even if the source argument falls, for a constitutional change can be major or profound without being a change to the sources of law. Indeed, the unique status of EU law in the UK constitutional order, pressed into the service of the source argument by the majority (-), can equally be seen as an explanation of why notification would effect major constitutional change.
Shifting emphasis away from the source argument does not resolve every contentious issue in Miller. The majority’s argument from constitutional change relies on a rather generous reading of the case law. Nevertheless, by focusing less on the distracting question of how to demarcate sources of law, the basic issue—what role the executive can have in shaping the British constitution—comes more clearly into view.
Hasan Dindjer is an Examination Fellow at All Souls College, Oxford.
(Suggested citation: H. Dindjer, ‘Sources of Law and Fundamental Constitutional Change’, U.K. Const. L. Blog (27th Jan 2017) (available at https://ukconstitutionallaw.org/))