These are extraordinary times.

We are jettisoning much of the post-war constitutional superstructure. We are losing the Charter of Fundamental Rights. The Prime Minister has signalled her intention to ditch the European Convention on Human Rights. The Government’s EU Withdrawal Bill places broad law making powers directly into the hands of Ministers. The devolution settlements are under explicit threat.  Cabinet Ministers are contemplating the reintroduction of a hard border in Northern Ireland.  The Government routinely ignores in part or in whole motions in Parliament. It acts in breach of constitutional conventions (para 150). “Senior Brexit Tory MPs,” it is reported, are taking legal advice on whether the Executive can ignore the Supremacy of Parliament. The Prime Minister appointed as her official spokesman a man, James Slack, whose ‘Enemies of the People’ front page incited threats against judges.

And the threat these extraordinary times poses can already, I believe, be seen in the operation of the rule of law in our highest court. Let me explain.

The central point in Gina Miller’s case was this:

when Notice is given, the United Kingdom will have embarked on an irreversible course that will lead to much of EU law ceasing to have effect in the United Kingdom, whether or not Parliament repeals the 1972 Act. As Lord Pannick QC put it for Mrs Miller, when ministers give Notice they will be “pulling … the trigger which causes the bullet to be fired, with the consequence that the bullet will hit the target and the Treaties will cease to apply”. In particular, he said, some of the legal rights which the applicants enjoy under EU law will come to an end. This, he submitted, means that the giving of Notice would pre-empt the decision of Parliament on the Great Repeal Bill. It would be tantamount to altering the law by ministerial action, or executive decision, without prior legislation, and that would not be in accordance with our law.

To address that point you would obviously need to consider whether “pulling the trigger” would have as its inevitable consequence the removal of legal rights. And the only court that could answer that question was the Court of Justice in Luxembourg.

But, as we know, the Supreme Court did not ask that question of the Court of Justcie in Luxembourg (despite the fact that it seems to have expected to be asked).

How did it avoid that course? Paragraph 26 gives you your answer:

In these proceedings, it is common ground that notice under article 50(2) (which we shall call “Notice”) cannot be given in qualified or conditional terms and that, once given, it cannot be withdrawn. Especially as it is the Secretary of State’s case that, even if this common ground is mistaken, it would make no difference to the outcome of these proceedings, we are content to proceed on the basis that that is correct, without expressing any view of our own on either point.

Gina Miller wanted to win; she was (then) happy to assert the Notice was irrevocable. For his part, the Secretary of State could not contend that the Notice was revocable because that would suggest, contrary to the Government’s policy, that the Notice might actually be revoked. And so the Supreme Court decided to assume that the Notice was irrevocable “without expressing any view of our own.” And, as we know, it went on to decide that the Government could not give the Notice without the permission of Parliament.

But here’s the thing.

It’s no part of legal reasoning to proceed on the basis of an assumption of the law. It’s logically impermissible. It risks wrong outcomes – with serious consequences. Let me illustrate the point.

I am one of six petitioners before the Inner House of the Court of Session in a claim asking for a reference to the Court of Justice on the question whether Article 50 can be unilaterally revoked. The case is likely to reach the Supreme Court. What happens if the question is referred to the Court of Justice which says the Article 50 notice can be unilaterally revoked?

It follows that the Supreme Court will have decided Gina Miller’s case on the basis of an flawed assumption of the law. But for that flawed assumption (many believe) the Supreme Court would have decided that the consent of Parliament was not needed to serve an Article 50 Notice.

Now, as it happens, Parliament did not, as the price of consenting, tie the Government’s hands to a particular negotiating objective. But it might, for example, have accepted the Lords’ amendment guaranteeing that EU citizens here continue to enjoy EU derived rights. It might have changed the course of Brexit and it might have done so without any proper legal basis. And that fact might have become known when the Court of Justice ruled on revocability. And all of those risks are why it is logically impermissible for a court (and especially a constitutional court) to proceed on an assumption of law.

So why did the Supreme Court take this course? Did it just forget this was impermissible and dangerous?

No. And here we delve into the realm of speculation. But my explanation is this: it was intimidated by the ferocious headlines in the Mail and elsewhere. It was spooked by the failure of the then Lord Chancellor to perform her constitutional duty to defend the judiciary. It felt threatened by Sajid Javid’s warning: “This is an attempt to frustrate the will of the British people and it is unacceptable.” It feared what would happen if it referred the question in circumstances where a referral would delay the Prime Minister’s stated intention to notify Article 50 by the end of March.

Let me put it bluntly. There is, I think, good reason to believe the Supreme Court was intimidated into acting contrary to the rule of law.

These are, indeed, extraordinary times.

And it is not sufficient to say, as many (including the Prime Minister’s former Chief of Staff) do, that “we” – whoever the “we” is in his sentence – can be trusted.

And it is not enough to assume that because things were fine fifty years ago they will be alright now.

We have no domestic written constitution. The extra-national constitutional structures are under explicit threat. There is good reason to think that the operation of the common law – that very British constitutional solution – has already been weakened by the prevailing climate. And, as my opening paragraphs point out, the Executive is running amok.

And this should alarm everyone – wherever they stand on Brexit.