My boyfriend's friend who works for brussels said the reason why Cameron is ******** himself is because all the member states agree minimum scope for a directive, these are then to be drafted into national law and they tend by necessity to take a sort of lowest common denominator approach but some governments, the UK especially take the opportunity to add extra details of unpopular law, and then claim that they have no choice about it, as it's a directive from Europe. If we vote leave, he will no longer have a scapegoat for unpopular legislation
Anyway, this is just an interesting fact to consider.