PUSH comes to shove, then, as Scotland muscles its way into the proceedings due next month at the Supreme Court in London, when the UK Government will appeal against the three judges’ decision that it cannot start Brexit without a parliamentary vote.

The Lord Advocate, Frank Mulholland, will be there to argue for the Scottish Parliament to have a say too. If he wins the point, he will vindicate Nicola Sturgeon’s assertion that Scotland is an equal partner in the UK. In that case, given how huge a majority there is at Holyrood against Brexit, she might even blow the whole process out of the water. At the very least, she is helping to tie Theresa May’s government in such fiendish knots that its plan of triggering Article 50 in the spring of 2017 starts to look a little optimistic.

Nicola is also doing the entire UK a service by helping to check executive abuse of power. But here I want to focus on a question which has received little attention – and that is how far, quite apart from the issues of Remain or Leave and Union or independence, all this is going to affect Scotland’s internal constitutional development.

Holyrood is a creature of Westminster, and as such it partakes of the basic doctrine of the British constitution, the doctrine of the absolute sovereignty of the Crown-in-Parliament.

We used to rail against this doctrine, for instance, when under Mrs Thatcher it was deployed to impose the poll tax on Scots against their clear wishes and to the financial detriment of many. The argument from north of the Border was founded on the principle of “no mandate”, but this never developed into a strong constitutional position. On the contrary, after the Scottish Parliament was set up, it in effect accepted without demur its role as a subordinate enforcer of the absolute sovereignty of Westminster. No doubt that came naturally to the first two Labour administrations, but little changed even when the SNP took over in 2007.

Though nothing has ever been said in so many words, it appears to me that the present Scottish Government believes in this absolute sovereignty too. Before the referendum of 2014, a lot of ideas were being kicked about on how we could shape the constitution of the new nation that would have emerged if the people had voted Yes.

When the Scottish Government published its white paper in advance of the referendum, however, it found little to say on constitutional matters. The only other guidance we have as to what, if anything, it had been thinking comes from its own behaviour – and that is not encouraging.

One clue appeared a couple of years ago in the course of the ill-tempered dispute that Alex Salmond’s justice secretary, Kenny MacAskill, had with the judges about the rule of corroboration in Scots law. The rule requires evidence against an accused person to come from more than one source. MacAskill proposed to abolish the rule, a move supported by one judge but, so far as we know, opposed by all the others. In fact there was general opposition from the legal profession. After MacAskill stepped down his successor, Michael Matheson, kicked the proposal into the long grass, and there it still lies. An attempt by the executive to coerce the judiciary, by means of a whipped majority of two at Holyrood, had been defeated

The affair was the product of a new constitutional trend in the English-speaking world. Our politics are becoming legalised, and disputes between executive and judiciary have grown more common. The tendency has been in recent times for the judiciary to extend its scope and, in particular, to increase its restraints over the executive and sometimes the legislative branches of government. No doubt this is some kind of intuitive response to the enormous expansion round the globe of the power of the state. The fresh legal restraints have not halted that, yet by judicial intervention the expansion has perhaps turned out a little less aggressive than it might have been. For this, the ordinary citizen can be grateful – especially in the UK, where his or her rights are not otherwise protected by a written constitution.

A stronger example than MacAskill and corroboration came with the three judges’ insistence on a parliamentary vote for Brexit. The UK Government was proposing to abuse its executive power by relying on the royal prerogative to launch the negotiations with the EU. The judges considered that, since the EU has conferred statutory rights on all of us, these rights can only in turn be removed by statute, which is made in Parliament: so Parliament must be involved. All this revealed more resilience in the UK’s constitution than I would have expected, given the rot in the rest of the state. Constitutions can evidently in themselves, though abstract in nature, evoke loyalty from the societies they underpin. We are bound to see more of that as President Donald Trump tries to twist and manipulate a constitution that in the US is positively revered. Clashes between executive and judiciary are normal there, with the judiciary usually coming out on top.

Till recently such clashes remained almost unheard of in the UK. We can see why if we look at some details of MacAskill’s spat with the judges. It may seem odd for him, a Nationalist lawyer, to have attacked a unique feature of Scots law, one on which it has long prided itself. He was responding to the feminist lobby which thinks it scandalous that only seven per cent of the rapes reported in Scotland result in a conviction. The nature of the evidence can obviously be a problem here, since sexual intercourse normally takes place between two people and no corroboration from a third is likely to be available. But to go from there to ending the rule for all offences is surely taking things a bit far. It would be in fact an attack on our human rights.

MacAskill explained himself like this: “Laws are made by parliament, not one profession. This is about having justice in our communities. It is not a debate between learned legal friends.” Here is a statement of the absolute sovereignty of Parliament that would shame nobody at Westminster. It is also unpleasantly rabble-rousing.

I am sure that over the next four years we will see attempts by President Trump at similar abuse of the office he has now won: rabble-rousing as the answer to inconvenient law.

But I am equally sure these attempts will all come to grief against a constitution founded on the separation of powers and the independence of the judiciary, and when all is said and done supported by the American people.

It will be a lesson for those in Scotland who, despite our experience in the UK, stick to the principle of absolute parliamentary sovereignty, as opposed to a system of checks and balances.

I hope the lesson will be learned by the time we come to write a constitution of our own.