The problem with the bankers analysis is that the EU has already tried to force clearing out of the UK, by passing regulations that openly violated the EU treat

The problem with the bankers analysis is that the EU has already tried to force clearing out of the UK, by passing regulations that openly violated the EU treaties themselves. The UK had to go to the highest courts to get the rules rolled back. It was a long and expensive legal process. The only reason the EU hasn't already tried to gut this business from the City of London is because their courts ruled they couldn't do that to an EU member, not through a lack of will. They certainly either don't think it'd be dangerous or (more likely) don't care. The people who run the EU are far more concerned with prestige than the details of these mechanisms. They don't like the UK, never have, and it bugs them that London - which doesn't use the euro - is so important to the parts of Europe that do. It's an itch they can't scratch.