The judgment’s basic thesis: the ECA’s requirement that no new EU treaty-based obligations and rights be introduced into UK law without “Parliamentary control” implies a “converse intent that the Crown should not be able, by exercise of its prerogative powers, to make far more profound changes in domestic law by unmaking all the EU rights” so introduced [93(8)]. The reasoning ignores the asymmetry between making treaty rights part of UK law and unmaking them by international action.

My JPP papers of 26 October and 2 November show that asymmetry’s significance. As I feared, the Government’s failed answers to the Court’s questions about unmaking treaty-based UK rights to relief from double taxation – rights that come into UK law by a single statutory provision combined with individuated Orders in Council (one for each of the UK’s 120+ double tax treaties) – have yielded a Judgment silent about that major category of UK treaty-based rights, uniquely analogous to ECA-based treaty rights.

The Judgment’s “clear and necessary implication” about Parliament’s 1972 intention is thus a highly improbable construct, a legal fiction.  Six days before the introduction of the European Communities Bill on 26 January 1972, the Commons heard a lucid exposition – directed to the Bill’s imminent unveiling – of double tax treaties and the way they come with great impact into UK law with some but not much Parliamentary control.   The exposition was by the leading public lawyer, Sir John Foster QC, MP.

In 1971, though he did not mention this, the UK Government had unilaterally terminated its double tax treaty with the Virgin Islands; in 1988 it unilaterally terminated the similar treaty, approved by the House of Commons in 1970, with the Dutch Antilles. In neither case does termination – fully authorized by a treaty provision, analogous to art. 50 TEU and like art. 50 given Parliamentary approval – seem to have needed or received any “Parliamentary control”. Yet, as Sir John pointed out to the House, 60 or 70 statutory rights come in if a tax treaty draft Order is (a) approved by the House (the Lords having no part at all) and then (b) takes effect internationally – when, while and for just as long as it does (he might have added, but the point is obvious).

Readers of my two papers will easily complete the analogy to Brexiting from the EU Treaties, and understand its bearing on Parliament’s really inferable intent.

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

Click here for further analysis of the Miller case.