IT’S got to the point where Brexit, though tedious in itself, makes us think critically about all sorts of other aspects of a disunited kingdom. In the last week two veteran politicians, Labour’s Gordon Brown and Tory Sir Malcolm Rifkind, have been lauding the referendum as the means to solve our big constitutional problems, Scotland to the fore among them.

Strangely, this is not a matter on which Brown the Unionist can boast any consistency. In 2008, while prime minister, he broke the promise made in an election manifesto three years earlier that under him the British people could be sure of one referendum, a direct vote on the European Constitution then being proposed in the Treaty of Lisbon.

After that we did not hear much from him about any other referendums. But since he retired from Westminster in 2015 he has several times emerged from the obscurity of North Queensferry to offer his opinion and advice on great questions of the day. He still sees referendums rather as a means of bolstering the sovereignty of the UK Parliament, which would have defined in advance the choices being allowed to voters. Beyond that, he is now tipped to head a new constitutional convention, though as it would only be appointed by Labour, and for Labour’s ends, it might not be his best claim to historical fame.

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Rifkind, former Scottish secretary and foreign secretary, was at the outset of his parliamentary career quite a keen devolutionist. He gave up this youthful folly so as to stake his claim to a seat in Mrs Margaret Thatcher’s Cabinet. Though also retired from active politics since 2015, he continues to serve his country as a pundit.

He has now ventured his view of the ideal status Scotland would enjoy at the end of another bout of constitutional upheaval. It would be one of four units in a federal system consisting also of England, Wales and Northern Ireland. Rifkind reaches this conclusion from two starting points.

The first starting point is that nobody wants to live in a UK with a central government as dominated as the present one is by English interests, and serving, for want of anything better, as the actual government of England. This will not be good enough for the smaller members of any successor Union.

The second starting point is that, on the other hand, few of the existing citizens in the Union’s four nations want it to be taken apart so decisively that they become almost aliens to one another, as if they belonged to the Irish Republic. This present Union may be fading away, but it should not become so ghostly as the Holy Roman Empire used to be. That, at its end, was abolished by Napoleon in a day.

Might we do better in terms of practical stability? Both Brown and Rifkind draw on talents and experience that could lead us to hope so. But the concept of federalism strains them. There has never been anything remotely federal about the UK. It’s a bit late to start.

For one thing, as a result of this centralised history pitifully few in our whole body of citizens are interested in federalism. So far it has been little more than an intriguing academic concept, a bit abstruse even for practical politicians, and with no real popular demand behind it at all.

What is more, the four nations approach it with different hopes and purposes. For half of Northern Ireland it could be a step into the open embrace of the Irish Republic, as a buttress for closer links that does not demand immediate incorporation.

That might also help to sell the idea in England, which has never enjoyed its fraught arrangement with Ulster. An England divided into Ulster-sized federal states (Yorkshire or the South West and so on) could possibly feel more comfortable with a federation that had this as its basic structure. It would certainly look more plausible than preserving the whole of England as one of the four units, in other words as a single federal entity.

In population it is already several times the size of any other constituent, in fact bigger than all of them put together. No federation in the entire world works with such an extreme disproportion at its core. England would continue to overbear the rest, making the whole exercise rather pointless.

It might at least be administratively tidier, but the trouble is that no public desire exists for such tidiness either. People would rightly ask what a new tier of government is supposed to do, when we have quite enough official functions being carried out already by their own expensive departments and civil servants, not all of them with any clear purpose. Countries can be over-governed, and perhaps the UK is one of them.

At any rate, national identity cannot be conjured up through laws. The English have been one people for 1000 years, and not a single part of the country shows the slightest taste for anything else. The voters put paid to federal ambition when they threw out the scheme of regional government dreamed up in 2004 by John Prescott. More recent experiments in urban management, called metropolitan boroughs, are not the same. They were never meant to set an example for the whole country. They are for cities, not the countryside, for the workers, not for the bourgeoisie, for the poor, not for the prosperous. And they have no role in nationhood, let alone in federalism.

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THE real test of a federation is where its sovereignty lies. True federations draw a deep division between the powers of the central authorities and the powers of the states, usually with a supreme court to adjudicate in cases of dispute. But for the most part, the sovereignty is exclusive to the one branch or the other, and these do not attempt mutual interference.

It is hard to imagine such an arrangement ever being accepted in or by England. Whoever runs the parliament at Westminster would continue to regard themselves as masters of the whole Union, and a majority of the population would probably agree with them.

But that majority would be the English majority in the entire UK. In other words, abuse of its authority would still be possible by a federal government in London. In the 21st century Scotland and England have been growing apart rather than growing together, a trend likely to continue. Whereas the English have not lost a taste for abuse of their power in Scotland, Scotland has never shown the same taste for abuse and is unlikely to do so now. Given this state of affairs, a true federation in the classical sense is impossible.

Under devolution, Scotland already has a constitution somewhat different and a Northern Ireland that belongs in part to the European single market will soon deviate more. Hardly anybody believes the UK can stay as it is, yet nobody is able to say (largely because nobody asked till last week) on what other terms it is going to survive. Boris Johnson and a few cyphers round him are content for nothing to be done. But that is the story of this government.