1. The European Communities Act 1972 was visibly crafted in every detail for a precise political-constitutional purpose, ignored by the Miller majority. The Act was to enable the UK to join the Communities – if and when the Government ratified the Accession Treaty – and to comply with all the UK’s rights-recognising obligations under those Treaties, while neither accepting nor ratifying the doctrine of the ECJ that by becoming a member, a state alters its own constitution, becoming no longer fully independent and sovereign but instead an element in a new legal order. Every detail of the 1972 Act treats the UK’s accession as occurring within the established UK constitutional framework, by which treaties are acceded to by the Executive and have effect in UK law if and only if, and just to the extent that, an Act of Parliament permits and defines (perhaps just one “ambulatory” Act applicable to many, many treaties, mostly not yet conceived at the time of its enactment).

2. In rejecting that clear Parliamentary intention, the majority holds (para. 68) that the ECJ doctrine in Van Gend en Loos [1963] and Costa v ENEL (1964) – that “independently of the legislation of member states”, EU law imposes obligations and confers rights within each Member state – became part of the UK constitution. The UK constitution itself, says the majority, was changed in 1972 so as to allow in a new and “independent… source of law” (paras. 65, 68, 80). The majority reject as “unrealistic” the demonstration by Lord Reed (with Lords Carnwarth and Hughes) that EU obligations and rights are effective within UK law only as dependent upon the 1972 Act, and that no constitutionally new source of law was brought in: the 1972 Act retained our constitution intact, notwithstanding the fecundity and practical importance of the EU law allowed in under the auspices of that constitution and its established sources and doctrines of law.

3. Judicial appeals to “realism” are not rarely a sign that the legal argument has been lost and the law is being set aside. So it is here. The majority’s relative inattention to the wording, logic and meaning of the 1972 Act – not to mention its real political purpose in the political context of 1972 — is remarkable. So too is the misreading of what was decided in Factortame (No. 2) (1991), and the brush-off attempt to distinguish ambulatory treaty application by the 1972 Act from the long-established method of ambulatory application of the UK’s scores of double-tax treaties, each wrongly said by the majority (para. 98) to require approval “by Parliament” (in truth only by the House of Commons).

4. Two quotations from Lord Reed’s dissenting judgment can suffice, for the purposes of this very preliminary Comment, to put the constitutional position plainly. First:

177:  … since the effect of EU law in the UK is entirely dependent on the 1972 Act, no alteration in the fundamental rule governing the recognition of sources of law has resulted from membership of the EU, or will result from notification under article 50.

The second passage takes for granted all that the judgment has already said about the long-established and indubitable limitations on the prerogative, about which the dissenting judgments do not differ at all from the majority. It attends to the concern that seems to underlie the majority’s legally ungrounded attempt to distinguish withdrawal from the EU from all other changes in the impact of EU law within the UK that might be accomplished by changes within the framework of the 1972 Act and without any further Parliamentary enactment – a concern about the sheer scale of the resultant change in legal rights and obligations:

240 …controls over the exercise of ministerial powers under the British constitution are not solely, or even primarily, of a legal character, as Lord Carnwath explains in his judgment [para. 249]. Courts should not overlook the constitutional importance of ministerial accountability to Parliament. Ministerial decisions in the exercise of prerogative powers, of greater importance than leaving the EU, have been taken without any possibility of judicial control: examples include the declarations of war in 1914 and 1939. For a court to proceed on the basis that if a prerogative power is capable of being exercised arbitrarily or perversely, it must necessarily be subject to judicial control, is to base legal doctrine on an assumption which is foreign to our constitutional traditions. It is important for courts to understand that the legalisation of political issues is not always constitutionally appropriate, and may be fraught with risk, not least for the judiciary.

5. Finally, a note for the Judicial Power Project: One of the least desirable features of modern adjudication (as I argued in my Judicial Power lecture in October 2015) is allowing the Court’s reasoning to be controlled by the concessions, oversights and failings of counsel, instead of by the law that even slight effort would show is controlling. So the intentions and provisions of Parliament get waved aside, all too often, because counsel has (for one reason or another) declined or failed to frame them robustly or in detail. This regrettable practice, which so short-changes the principle of legality and the Rule of Law, is yet again on display in the majority judgment. For instance: counsel on all sides neglected to analyse the constitutional model that Parliament was quite obviously following in 1972. That was the model established by the UK’s ambulatory importation of double-tax treaties, which (by virtue of a single statute) have multiple, various, changing effects in our law “notwithstanding anything in any enactment” (!). Counsel for the Government declined to take the Court through this illuminating structure, partly (he told the Supreme Court) out of “cowardice”, lest he be asked questions he couldn’t answer. This failure should have made the majority work to understand this legal structure and its analogy (not identity) with the ECA 1972 and the Treaties, before making their at best dubious claim that the 1972 Act was “unprecedented” (para. 60).  Instead, they shrugged the matter off (see para. 98).

6. Since the majority virtually ascribes to me (para. 65) the Government counsel’s “conduit” metaphor (to describe the method of importing double-tax treaties or European Treaties), I may mention that counsel was deploying it (in relation to the latter!) in the Divisional Court, long before I ever said or wrote a word about these matters. As the majority could have discovered in two or three minutes, the metaphor’s use was not “echoing” me at all. For the reason I mention in my Sir Thomas More Lecture (put before the Court and relied on by the Government), and for other reasons too, it is not a great metaphor for the homegrown, British constitutional mechanism for giving ambulatory and anticipatory statutory effect to treaties to be made and unmade by our Executive, for just as long as they are in force and without further statutory authority for their making or unmaking.

7. The necessary constitutional authority for an Executive art. 50 notification was supplied by the constitutional mechanism adopted by Parliament in its 1972 Act, when that statute is interpreted with the sort of faithful attention to history and wording that is a feature of our Parliamentary, legal and constitutional thought and practice – as distinct from Europe’s.

John Finnis QC FBA is Professor Emeritus of Law in the University of Oxford.

Click here for further analysis of the Supreme Court’s Miller judgment.