My first post attracted a lot of readers, so I think I should try to expand a bit and be more precise.
The UK is no longer politically credible as a single - state entity. The constitution is anachronistic (unelected House of Lords) and lopsided (no English parliament). The political system lacks legitimacy - voter turnout is low (36% in the recent Barnsley bye-election) and the electoral system inherently unfair. Politicians are widely distrusted (to put it politely).
What are the ways out and ways forward?
OPTION 1. A federal system. Each of the UKs four components has a parliament with identical powers and a federal parliament deals with all-UK questions like defence and foreign affairs and major taxation matters. This system could also accommodate the Channel Islands and Isle of Man whilst closing down their tax haven businesses which drain the UK Treasury of funds. Each component would fly its own flag alongside the UK flag. (In Europe, it's common to see town halls flying the national flag and the EU flag side by side).
The drawback of this scheme is that it is a bureaucrat's dream.
OPTION TWO. The break-up of the UK. One or more of the four constituent parts takes full independence and leaves the others to sort themselves out as best they can. This doesn't entail that relations between Outs and Ins become hostile. Indeed, the opposite should be the case. The Republic of Ireland is entirely independent of the UK but has bi-lateral arrangements which make things like travel in both directions easier than they would otherwise be. The Republic is much more popular as a holiday destination for English tourists than the North.
Break-ups can be civilised. The obvious case is the separation of the Czech Republic and Slovakia by consent. Importantly, Slovakia seems to have done very well out of going for full independence, with strong economic growth and even qualifying for entry to the €uro zone ahead of the Czech Republic.
The potential disadvantage of this scheme is that the four components go off in such different directions as to make business and everyday life complicated and inefficient. Scotland might want to stay in the EU and adopt the €uro; England might want to leave the EU and certainly would want to stick with the £.
Though I think the €uro is a great acheievement and the Schengen Area also, I can see that non-EU countries are not nasty countries: Switzerland and Norway are not on any axis of evil. One is quite conservative, as a result of its Referendum - based politics, the other is socially progressive. But both are members of the EUs Schengen Area and both adopt swathes of EU legislation as if it was their own.
Those who want to defend the existing order of things are afraid that an independent England (though, curiously, not an independent Scotland or Wales) would turn into a nasty Nationalist, xenophobic, Islamophobic, football-hooligans' paradise. Maybe a bit like France.
I think the opposite might be the case. If England was an independent nation, it might actually be quite a tolerant and progressive country. Of course, it would have right-wing and left-wing parties. There would be voters both pro and anti Europe. There would be anti-immigrant people and Open Borders people. There would still be the Bankers.
So English independence would not automatically solve political issues and conflicts. But it would create a better constitutional and political framework within which they could be dealt with.
It would also ease the resentment clearly widely felt in England that Scotland, Wales and Norther Ireland get a (subsidised) better deal than they deserve. Since the Scots at least think the subsidy runs the other way (because of North Sea oil), neither side would feel disadvantaged if it took its independence. So independence is a win-win option for both England and Scotland. For Wales and Northern Ireland this is not so obviously the case, but they might take heart from the case of Slovakia, which was the poorer half of Czechoslovakia until it decided to break away.