Bloody British immigrants, flooding the UK !
If it comes down to it, "mutual agreements" will be put in place. By population London is France's 6th largest city, as it were, and many EU countries would be pretty inconvenienced if the current regulations were dropped on the spot vis-a-vis Brits and living in Britain.
MrsB nearly had kittens yesterday when she read a scare piece (turned out to be just a blog) suggesting that expat Brits living in the EU would lose their reciprocal health care rights with a Brexit.
But Cameron is a right arse for raising even the possibility of such chaos in the first place. Trump is rated at about 20% to become next POTUS and that is a truly ridiculous prospect yet far from impossible. Brexit is somewhat more likely, if the bookies are right.