A repeal of the Act of Parliament uniting England and Scotland as a single political entity, thus paving the way for both countries to emerge as sovereign states in their own right.
Why does this idea matter?
The current political make-up of the United Kingdom is fractured and inbalanced. The Scottish Parliament is responsible for some issues within Scotland, the UK Parliament for others. There is no equivalent English Parliament, so England is governed directly by the UK Parliament. Scotland at least has a government which can stand up for Scottish matters, whilst the UK Government always has to consider what is best for the UK as a whole, not what is necessarily best for England. And Wales has an assembly that has to ask Westminster's permission to do anything.
The political and economic situation these days is far removed from those at the beginning of the 18th Century when the Union was born. We have strong ties with our European neighbours, and good relations with many other countries around the world. Our economy is robust enough to ride out the storm we are currently in. Dissolving the Union will not lead to economic collapse, nor will it push us out into a political wilderness. What it will do however is free both England and Scotland to persue their own goals in a manner their people demand, without the shadow of an outdated UK government looming over them making sure that they act in 'Britain's best interests'.
It would also put an end to the contentious issue of funding, which is turning ever more into a septic wound in relations between the two countries. Scotland can have its oil revenues, England can finally be rid of the hated Barnett Formula.
We've been together for 300 years, and we've done an awful lot of good stuff in that time. But every party has to come to an end sometime, and I think the Union is no longer as relevant to either country as it once was. Indeed, it appears more antagonistic now that ever. England and Scotland are both grown up enough now to go their own seperate ways, and to make a success of it. Independance for England and Scotland means sovereign governments that can act in the best interests of the English and the Scots. And that has to be good for democracy.
As for Wales, well the 1707 Act of Union did not specifically mention Wales, as at the time it was deemed to be part of England. But we live in a democracy, and Wales is just as entitled to have a say on its future as England or Scotland. If the Welsh wish to go their own way, so be it, and the best of luck to them.