Some reactions to the High Court’s judgment in the article 50 case, R (Miller) v Brexit Secretary, have been ugly, excessive and ridiculous. It’s excessive too to see the judgment as blocking Brexit, or as creating a constitutional crisis. It does neither thing. I’ve no doubt that if the judgment is upheld on appeal to the Supreme Court, the government will obtain the one-clause bill it’d need authorising it to give notice of Brexit under the famous article 50.

But the judgment is surprising (I expected it’d agree with my view), it’s problematic, and I think it’s wrongly decided. Here’s why. I’m afraid my explanation is long: but I think it needs to be.

The basic flaw

In broad terms, what’s happened is that two recently discovered or “upcycled” legal doctrines—the theory that there is a higher class of “constitutional” statutes and what’s called the “principle of legality”—have combined with, I think, confusion about the effect of the European Communities Act 1972, and created a heady and intoxicating legal brew. Deeps draughts of that stuff have impaired the bench’s judgement so much that they’ve thought constitutional principle required them to take and upside-down approach to statutory interpretation, and read the 1972 Act in a way Parliament can surely never have intended either in 1972 or since.

The underlying principle

First, it’s important to be clear what legal principle the judges have tried to give effect to. It’s not that there’s anything really unusual about article 50 that means ministers can’t “trigger” it using prerogative powers, or even that doing so would deny people their rights. It’s a much broader constitutional principle that the court derives from the 1610 Case of Proclamations (paragraph 27 of yesterday’s judgment) that the executive by prerogative

cannot change any part of the common law, or statute law …

and from the Zamora case in 1916 (para. 29 of the judgment):

The idea that … the Executive, has power to prescribe or alter the law to be administered by Courts of law in this country is out of harmony with the principles of our Constitution.

That’s worth remembering: the High Court thinks triggering article 50 would change the law in this country, and that no change to the law of any kind can be made by doing so. The principle is much wider than, for instance, one that only protects fundamental constitutional or human rights. But almost immediately after explaining it, the court undermines it by accepting (para. 33) that

treaties can have certain indirect interpretive effects in relation to domestic law …

Which they certainly do. The courts presume Parliament to legislate in accordance with the UK’s international obligations which means, if you think about it, that merely entering into a treaty alters our law here to some extent. But, the court says (§33)

this does not affect the basic position that the Crown cannot through the use of its prerogative powers increase or diminish or dispense with the rights of individuals or companies conferred by common law or statute or change domestic law in any way without the intervention of Parliament.

But the exception surely does blow a hole through “the basic position” as outlined by the High Court. Judges themselves have said international obligations alter to some extent the law in this country.

EU law rights

Next, let me turn to what I think are the court’s misunderstandings about the EU rights, and the effect the 1972 Act had in bringing them in to our legal system. First, the court at §34 says

a direct link exists between, on the one hand, rights and obligations arising through action taken on the international plane – by entry into and continued membership of the … [EU] … and creation of EU law in the relevant Treaties and by law-making institutions of the European Union – and, on the other, the content of domestic law. This is the result of a combination of principles of EU law, including principles of direct effect of EU law in the national legal systems of Member States, and the terms of the ECA 1972 …

On its face this is unobjectionable; but I wonder whether underlying the judgment is an unspoken assumption that the EU law concept of direct effect makes these treaties and this legislation unique by giving EU law some independent status in our own law. That’s certainly not right: it’s only by artificial statutory domestication of the concept of direct effect through the ECA 1972 that EU law has effect here. The passage I’ve just quoted leaves some room for doubt about how clearly the High Court saw this, and my slight doubt are increased by §42 of the judgment where I think the court may not be quite right to imply EU law requires the concept of direct effect to be explicitly transposed into national legislation.

The judges go on to set out (§§57-66) three categories of “rights” they say are relevant. The first, “category (i)” are rights like equal pay or working time restrictions that can be replicated nationally. This is unproblematic. The second, “category (ii)”, are rights British citizens enjoy in other countries because of EU law, such as the right to take a job in France and not be discriminated against. It’s far less obvious why the court thought these rights—which cannot possibly exist in our domestic UK law—are relevant. The third “category (iii)” is what you might call pure institutional EU rights such as the right vote for MEPs or to ask a court to refer a point of interpretation to the European Court of Justice.

The High Court says article 50 notification would remove category (i) rights, but of course it would not: there might be a “soft Brexit” in which many of those rights are actually retained. It’s interesting that (§64) that the court needs to bolster its reasoning by referring to the ancillary loss of the category (i) right to ask for a reference to the ECJ.

But the reasoning of the court concerning category (ii) rights is very odd. These are plainly nothing to do with UK law or with Parliament: your or my free movement rights in France derive entirely from whatever effect the EU treaties have or are given in French law by French legislators and courts. And the High Court admits (§66) that

In a highly formalistic sense, this may be accurate

which is now my favourite euphemism for “it’s right but I reject it”. The High Court is quite correct (§66) to say

withdrawal from the European Union pursuant to Article 50 would undo the category (ii) rights

but what’s wrong, bearing in mind the constitutional principle underlying the judgment, is to think undoing category (ii) rights would change UK law in any way. It wouldn’t.

Only category (iii) rights actually fit unproblematically into the court’s analysis. They would undoubtedly and necessarily end at the moment (not of article 50 notification, but) of Brexit. So the court’s reasoning is actually based on the extinction of fewer rights, and the alteration of less UK law, than it seems. And it really only comes down to EU citizenship and the right to vote for MEPs or stand as one. The supposed right to ask for a reference to the ECJ is actually a power for courts to decide to make a reference. It’s not a substantive right at all, but just a procedural right to make an argument in a UK court.

An intriguing point, in passing

It’s interesting at this point to look at §70, which mentions without judicial comment that the European Parliament became directly elected in 1979. One wonders, if the High Court is right, what legal power the government had in the 1970s to agree to the change before MPs passed the legislation. Remember, it’s not just prerogative action that (in the judges’ view) removes rights that they say’s unlawful; the idea is that it’s unlawful by prerogative to alter the law in any way.

The real meat of this judgment, though, and where it really goes astray, is in the discussion on statutory interpretation from §77 and especially from §82.

Interpretation, and the two questionable principles

At para. 44 the court had mentioned the principle put forward by Lord Justice Laws in Thoburn that the ECA 1972 is a “constitutional statute”, with the technical legal consequence that it can only be amended or repealed explicitly. That’s always been an unconvincing theory, not much backed up by subsequent cases from higher courts. Frankly, it’s wrong. The way the ECA 1972 interacts with later statutes is (as seems to me obvious) because of its wording and what Parliament must have meant by it, rather than its status. But even if it’s right, Laws’s “constitutional statute” theory is limited to shielding the 1972 Act from accidental repeal.

In yesterday’s judgment, though, the thought seems to have grown into a wider proposition (that I detect underlying §§81-88 of the judgment) that a cross-cutting constitutional principle must implied into a “constitutional statute” that neither Parliament except by express words nor government can do anything that would on any view affect it in any way at all. It finds eventual expression in §88:

Since in enacting the ECA 1972 as a statute of major constitutional importance Parliament has indicated that it should be exempt from casual implied repeal by Parliament itself, still less can it be thought to be likely that Parliament nonetheless intended that its legal effects could be removed by the Crown through the use of its prerogative powers.

This is I think a vague and unjustified expansion of “constitutional statute” theory. Even if Laws LJ in Thoburn was right, his principle was about the way later legislation affects the 1972 Act. It has nothing to do with the prerogative.

This expansion of “constitutional statute” thinking has happened because the court has mixed it with the “principle of legality” that’s especially fashionable at the moment (in Evans in the Supreme Court, notably). According to that principle, which Lord Browne-Wilkinson traced in Pierson to academic writings and to a series of cases in the 1980s and 1990s, Parliament is presumed not to have intended to change the common law unless it has clearly indicated such intention.

Extraordinarily, the High Court has now reversed the principle in such as way as to presume that Parliament in 1972 did change the common law (by curtailing prerogative powers) although there are no clear words in the 1972 Act doing so.

It’s clear, then, that the heart of the problem in the judgment is the “flip” the court makes in §84 onwards, when it rejects the argument that

language would need to be found in the ECA 1972 before it could be inferred that Parliament intended to remove the Crown’s prerogative power

and concludes the opposite, that clear language would need to be found preserving the prerogative. This is, in my view, the fundamental flaw in the High Court’s reasoning.

The Rees-Mogg case

At §§90-91 the High Court distinguishes the Rees-Mogg case that I think raises the same essential issue as article 50. It does so by saying Rees-Mogg was not a general ruling that prerogative powers had survived the 1972 Act, but held merely that ministers could ratify the Maastricht treaty by prerogative because the social protocol did not change UK law.

Frankly, this is an implausible and untenable reading of the Rees-Mogg case. It’s plain if you read the judgment that what the High Court calls the “nub” of the reasoning in Rees-Mogg was actually a back-up argument bolstering its primary legal conclusion, that

When Parliament wishes to fetter the Crown’s treaty-making power in relation to Community law, it does so in express terms … There is in any event insufficient ground to hold that Parliament has by implication curtailed or fettered the Crown’s prerogative to alter or add to the E.E.C. Treaty.

Finally, paragraph 93 of yesterday’s judgment is odd. In it, the court identifies what it sees as textual support for its interpretative approach—but the points it makes are unpersuasive. Its point (3) in particular is very opaque. And what need, anyway, for textual support to bolster a reading that (according to the judges’ reasoning) follows implicitly from constitutional principle? Paragraph 93 reads, to me, like a suspiciously overdetermined and thin belt adding little to the courts’ already dodgy braces.

I wish I thought the Supreme Court would reverse it

If this judgment is correct, its consequences are, I think, radical and surprising. If in 1972 Parliament really did end the government’s power by prerogative to (as the court thinks) change UK law by doing anything that alters EU law, then surely every change to EU treaties agreed by Prime Ministers has been unlawful. Why, if this judgment stands, was it lawful for Mrs Thatcher to agree to the Single European Act? Why was it lawful for Mr Blair to sign up at Amsterdam to the Social Chapter? The High Court implies in its treatment of Rees-Mogg that he had no prerogative power to do so.

The list of worrying consequences goes on. What power have ministers ever had to agree in Brussels to EU measures such as Directives that (as the High Court sees it) change the law in this country when adopted? It seems to me at least arguable that, according to the High Court, all of this was unlawful—and that, to act lawfully now, we must all behave as if Britain were still in the European Community as it existed on 1 January 1973, before ministers by prerogative “unlawfully” made any changes. The solution to this conundrum can’t be that Parliament later “cured” ministerial unlawfulness by confirming the changes they’d agreed; if that were the answer, then the government’s planned “great repeal bill” could cure the supposed unlawfulness of article 50 notification.

I wish I thought the Supreme Court would reverse this—a judgment that’s tempered the twin edges of constitutional statute theory and the “principle of legality” and made of them a weapon that can be aimed at Parliament as it was, yesterday, at government. But the Supreme Court likes the principle of legality too much. We can hope for some dissent there, but I expect it to uphold this wrong turning in constitutional law.