Cameron has announced that June 23 will be the great vote on whether the UK sticks with the EU (with a lot of new concessions hammered out in the past week to address British concerns) or whether it pulls out entirely.
The great irony is that it seems like Great Britain just went through this with Scotland, but the issue is that while Cameron and his party supported keeping the Union together, all the pressure for ditching the EU is coming from his party. And he’s got at least 6 of his own cabinet backing Brexit openly. Polls indicate it’s very close. The newest update is that Boris Johnson, conservative mayor of London and potential future PM, just threw his weight behind Brexit.
It’s hard to see Brexit passing without all the constituent parts of Great Britain wanting to do the same thing. The Scottish independents will want another go, and god help them if Northern Ireland and Wales start feeling the tug.