If UK leaves EU what about expats?

“Is it not in Britain’s national interest to argue for changes which... will strengthen and sort out the relationship between Britain and the EU, and then to ask the British people for their consent?” asked Mr Cameron during a recent Commons question time.
Any new terms are unlikely to affect Britons in France, said Christopher Chantrey, chairman of the Paris branch of Conservatives Abroad; though he said there is a risk they would tarnish Britain’s image, with the UK being seen as only in the EU for its own benefit.
“I think the basic rights will be still there, I can’t see other states agreeing to any changes to them – one of them being freedom of movement. It’s going to be things like the working time directives and legislation on pay.”
It was unlikely Britain would leave the EU. “I think realism will prevail as people realise there’s too much to lose.”
Question marks do remain however, over the result if new terms are turned down at a referendum or if they are not agreed by the other states.

Back to 1973
If Britain comes out, there is a risk we would “go back to where we were before 1973,” Mr Chantrey said.
“You had to have a foreigner’s resident’s card and it was much more bureaucratic. We wouldn’t have a right to be here; we’d only be here if the French didn’t mind.”
Franco-British avocat Gérard Barron of Boulogne-sur-Mer said refusal by other states of a renegotiation could mean Britain having to make a decision on staying or leaving.
This would require a referendum, which in turn would mean “a very long and heated debate in both parliament and the media” before it took place. “I don’t think people are stupid. Once they have totted it up they will realise that in the long term it might mean they won’t be able to go on holiday on the continent any more because the pound could become like the Moroccan dhiram [worth e0.09]; they will lose at least half of their trade with Europe and have to import more. I think everyone would vote to stay in.”
If the opposite happened, there would be transitional arrangements over at least two or three years, ensuring British residents did not immediately lose current rights, he said. However ultimately Britons would be in the position of other non-EU nationals - they would need to apply for residency permits from the prefecture.
With regard to healthcare, étrangers with residency cards have the right to the CMU (free membership of state healthcare for those on the lowest incomes, or otherwise membership via payment of a percentage of income).
Even if the renegotiation fails, chances are “close to zero” Britain would sever all ties, Mr Barron said. What is more likely, would be retaining membership of the EEA, like Switzerland or Norway. “This gives everyone virtually the same rights, but the British government would have no say in how the EU is run.” Britons would keep the same residency and healthcare rights, he said.