Originally Posted by Chris

The UK has a permanent opt-out from the Euro. There are other measures due to become permanent over the next couple of years, that is definitely ringing a bell, but I can't remember what they are.

In any case, it wouldn't matter - Cameron is talking about changing the treaties that form and govern the EU. There is nothing done that cannot be undone by a new treaty. The trick is whether he will get a new treaty, and whether it will contain what we want.