I've said this before and I'll say it again, no PM/Government is dumb enough to try and take the UK into the Euro, any referendum on it would be lost and if they took us in without one they would never be elected again, people may not understand the EU constitution and what it gives away, but everyone understands the difference between a pound and a euro, and just how bad giving away control of our currency would be.
Quite. But the creation of the current finanacial services supervisory structure has a great deal to do with the preparations for joining the euro, partially being a consequence of the independence of the Bank of England.
This is a horrendously complex issue, and I am working up a new post to go up sometime later today ... I hope.