[jcranmer]

> Now, which member might actually go veto a catalanian EU-membership?

Spain, for starters. Belgium and Italy might consider it as well. Basically any country that has a notable successionist movement.

That's one of the things that was pointed out during the Scottish independence referendum: contrary to the SNP's hope, the EU pointed out that membership was not going to be automatic, and Spain did signal that it was not going to look kindly on Scotland applying to join.