It completely rejects the arguments advanced by the Attorney General for the government. Triggering Art 50 to start withdrawal from the EU requires Parliamentary approval not in the form of a vote but in the form of a statute. It would be extremely surprising if the Supreme Court reversed the decision. The government’s Brexit plans have suffered a major reverse.’

The decision provoked disturbingly offensive front-page newspaper headlines of a kind rarely seen in this country, adorned accusingly by large pictures of the three judges: ‘The judges versus the people’ (Daily Telegraph), ‘Enemies of the people’ (The Daily Mail), ‘Three judges yesterday blocked Brexit, Now your country really does need you’ (The Daily Express) and more of that ilk. The Lord Chancellor, Liz Truss, with statutory responsibility to uphold the rule of law, was rightly criticised for her feeble response to such gross media excesses.

Judgment in Miller and Dos Santos v Secretary of State for Exiting the EU [2016] EWHC 2768 (Admin) was given on 3 November by Lord Thomas, Lord Chief Justice, Sir Terence Etherton, Master of the Rolls and Lord Justice Sales. The decision ended: ‘For the reasons we have set out, we hold that the Secretary of State does not have power under the Crown’s prerogative to give notice pursuant to Art 50 of the TEU for the United Kingdom to withdraw from the European Union’ (at [111]).

A few days earlier, Mr Justice Maguire in Northern Ireland had reached the opposite conclusion (Re McCord’s Application [2016] NIQB 85). The English decision considered that Northern Ireland decision and rejected its reasoning.

The court’s judgment said it was agreed between the parties that once given, notice of intention to withdraw from the EU under Art 50(2) of the Treaty on European Union (TEU) could not be withdrawn. In the Northern Ireland case, Maguire J held that the effects of giving notice would only occur at the end of the process. The English court disagreed. It accepted Lord Pannick’s contention for the claimants that giving notice was like firing a bullet. Since it could not be recalled, its effects had to be judged from the moment notice was given.

Unless all 27 other member states agreed to an extension, the court said: ‘Once a notice is given, it will inevitably result in the complete withdrawal of the United Kingdom from membership of the European Union and from the relevant Treaties at the end of the two year period. . . The effect of the giving of notice under Art 50 on relevant rights is direct, even though the Art 50 process will take a while to be worked through’ (at [11]). The effect of notice on relevant rights deriving from the European Communities Act 1972 (ECA 1972) included their removal.

The government argued that rights obtained under statute could be removed through use of prerogative powers provided that Parliament had not expressly abrogated the powers either expressly by statute (citing R v Secretary of State, ex p. Rees-Mogg [1994] QB 552 (DC)), or by necessary implication from a statute (citing AG v De Keyser’s Royal Hotel [1920] AC 508). ‘No words could be found in the ECA 1972 or any other statute which abrogated that power expressly or by necessary implication’ (at [76]).

The court said that statutory interpretation – and especially of a constitutional statute such as the ECA 1972 – had to proceed ‘having regard to the background of constitutional principles which inform the inferences to be drawn as to what Parliament intended... Where background constitutional principles are strong, there is a presumption that Parliament intended to legislate in conformity with them and not to undermine them’ (at [82]).

The government’s submissions on s 2(1) of the ECA 1972 ‘gave no value to the usual constitutional principle that, unless Parliament legislates to the contrary, the Crown should not have power to vary the law of the law by the exercise of its prerogative powers’ (at [84]). In the court’s view, the Secretary of State’s submission was ‘flawed at this basic level’ (at [85]).

The wide and profound extent of the legal changes in domestic law created by the ECA 1972 made it especially unlikely that Parliament intended to leave their continued existence in the hands of the Crown through the exercise of its prerogative powers. ‘Parliament having taken the major step of switching on the direct effect of EU law in the national legal systems by passing the ECA 1972 as primary legislation, it is not plausible to suppose that it intended that the Crown should be able by its own unilateral action under its prerogative powers to switch it off again’ (at [87]).

The Crown had untrammelled power to act on the international plane, but that did not extend to withdrawing from the relevant EU Treaties where such withdrawal would, as the Secretary of State conceded, have a major effect on the content of domestic law. There was nothing in the ECA 1972 or in later statutes that expressly or by necessary implication gave the executive such power. The court said it was clear that in enacting the 1972 Act Parliament intended to introduce EU law into domestic law in such a way that it could not be undone by exercise of Crown prerogative. It therefore had no prerogative power to effect a withdrawal from the relevant treaties by giving notice under Art 50 of the TEU.

The court said it had reached its conclusion by considering the ECA 1972 and basic constitutional principles. It had not found it necessary to deal with a number of other arguments advanced by the claimants.

The Northern Ireland case

But the court did devote a page to Maguire J’s decision of a few days earlier in the Northern Ireland case. The judge in McCord had rejected the applicants’ argument that the executive’s prerogative power to give notice under Art 50 had been displaced by the Northern Ireland Act 1998. But that was the wrong starting point ‘because a prior question [was] the effect of the ECA 1972 on domestic law and the Crown’s prerogative powers’ (at [104(1)]).

The judge had failed to address the principle that the Crown cannot through its prerogative power change any part of the law of the land. Nor had the judge the advantage of careful analysis of the effect of Art 50. It was therefore unsurprising, the court said, that he had concluded that notification under Art 50 would only ‘probably’ ultimately lead to changes in UK law when it had been accepted by all sides in the case before the English court that it would necessarily have that effect. He had also said that Parliament would legislate to determine the application of EU law after withdrawal whereas the Secretary of State had told the court that when withdrawal from the EU took effect, all EU law would be stripped of its effect in domestic law without any requirement of further primary legislation.

The declaratory relief granted by the court, as requested, was simply that the Secretary of State does not have power to give notice under Art 50. The words ‘without an Act of Parliament’ had been withdrawn by the claimants in order not to offend parliamentary sensibilities. But there is no doubt that the court’s judgment requires a statute giving the Secretary of State power to activate Art 50. Rights created by statute can only be taken away by statute. Mr David Davis, Secretary of State for Exiting from the EU, conceded that was the case.

The court gave permission for a leapfrog appeal to the Supreme Court and the government immediately stated that it would appeal. I would be surprised if the Attorney and his team of supporting QCs and other lawyers have given Ministers reason to hope that there was any great hope of the Divisional Court’s unanimous and very strong decision being reversed.

The appeal is to be heard in December for the first time with all 11 Justices sitting. The hearing will be accessible worldwide live-streamed. In my view the government could be looking at losing 11-0.

Contributor Michael Zander QC is Emeritus Professor, LSE

This article was originally published in New Law Journal