THERESA May was up here yesterday. Remember her? She’s still Prime Minister, apparently.

It was rather nice to see her, for nostalgia’s sake, like when you spot your old maths teacher browsing the yoghurts in Tesco. She may have lost control of the class and had to take early retirement, but she suddenly looks a whole lot better than the ingratiating probationers vying to take her place.

And she is worried. It turns out that all those warnings that a hard Brexit could break up the UK have not fallen on deaf ears after all. Like David Cameron, she’s trying to woo Scotland with a new initiative – not new powers, but a review, to make sure UK government departments are working in the best interests of devolution.

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Too little too late, says Nicola Sturgeon, but it is at least a frank acknowledgement of an unavoidable fact: that there has been an ongoing failure in Whitehall to understand and appreciate the Scottish perspective. The collective eye-roll when the word “Scotland” is mentioned, in other words, has to stop.

Ms Sturgeon, as ever, is one step ahead of her. She has already announced a new initiative that reflects dissatisfaction with the way devolution is working, the so-called Citizens Assembly, tasked with considering what sort of country Scots want to build and how to “overcome challenges” like Brexit, a move widely regarded by pro-UK supporters as a Trojan horse for independence.

Well, even if it were secretly intended that way, a Scottish Citizens Assembly would in practice be hard for Ms Sturgeon to control. It could be a valuable exercise.

The trouble is that it’s only part of what we now need. The next step surely has to be a UK Citizens Assembly. While a Scottish one could consider independence or the status quo, they are not the only options. A move towards federalism, for instance, would require buy-in from the rest of the UK. And in any case, it’s not just the relationship between Scotland and England that isn’t working properly, but between the English regions as well.

A Citizens Assembly is the product of Newton’s Third Law as applied to politics, the “equal and opposite reaction” to the Brexit referendum. If the Brexit vote was the archetypal example of a complex, multi-faceted argument being boiled down to a woefully simplistic binary choice, a Citizens Assembly is the opposite, a representative group of voters spending days or even weeks getting up to speed on the issues and then, after much discussion, coming up with proposals for a way forward. It recognises that the best choices are made when people are well-informed and have the space and time to think – the basis, after all, of the way parliaments work, with their emphasis on committees that take evidence.

This example of so-called deliberative democracy is now being endorsed by everyone – the House of Commons recently announced one to consider climate change – partly as a way to re-engage disaffected voters and partly because, as Brexit shows, when difficult decisions have to be made it’s a good idea to get voters’ help in making them, instead of misleading them about how easy the choices really are.

So a UK Citizens Assembly could be instrumental in helping reform the way the UK works.

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Imagine a UK Citizens Assembly in which Scots were able to take the floor to explain to their English friends what it really means to be Scottish. Imagine having the opportunity to point out why Scotland is not a “region” but a country – a country, moreover, which arguably has a stronger sense of national identity than England does. Understanding this critical difference between the “nations” and the “regions” of the UK – often lumped together as if they mean the same thing – is key to finding a solution to the problems of devolution.

But Whitehall, Westminster and many voters in England, still do not understand why Scotland believes it has the right to be treated as an equal partner with England when it has a tenth of the population.

And why would they? The fact that the Westminster parliament is still the English parliament enshrines the idea that because England is bigger, then the choices of its voters must naturally prevail.

The UK Government has talked about a partnership of equals, but since the high tide of anxiety about Scottish independence in 2014, things have returned to something like business as usual. The casual announcement in 2017 by the UK Government that it would retain 111 powers returning from Brussels, even though they concerned devolved issues, was so tone deaf that even Scottish Tory MPs despaired.

Did the UK Government backtrack? To some extent, relinquishing its grip on most of those powers. Did the SNP administration in Edinburgh milk the saga to make devolution look “broken”? For sure. But it was essentially a mess of the UK Government’s own making.

That’s why we need a UK-wide conversation. And if Scots want to consider federalism as a solution to the problems besetting devolution, then England (and indeed Wales and Northern Ireland) should be given the chance to consider federalism as a solution to the inequalities created by having such a London-centric economy. The long-running counter argument, that there is little enthusiasm for regionalism in England, may not be valid for much longer. The stark division between London and the rest of England was laid bare by the Brexit referendum.

Meanwhile, the Scottish Citizens Assembly, if truly left to its own devices, could consider some of the thornier questions about the costs and benefits of greater autonomy, up to and including, but not restricted to, independence.

Unfortunately, because Nicola Sturgeon wrapped up her announcement of it with talk of another independence referendum, its image has been somewhat compromised. A backlash from pro-UK parties has duly ensued. The Assembly’s chair, the former Labour MEP David Martin, has called for anti-independence supporters to give it a chance, but he has not been helped by the SNP MP Joanna Cherry, who describes the Assembly as “the perfect way” to “move us towards independence”. Sigh.

Politicians need to back off now. If we’re going to have a Citizens Assembly, then let’s leave it to the citizens. Let’s have a British one as well as a Scottish one, and throw the whole constitution open for debate. God knows, it’s about time.