Hold on to your top hat here, this is a direct quote - no my words, from an article I linked to...
6. Clearing – the end of the world as we know it?
The nuclear scenario is that the European Central Bank will force the relocation of clearing of euro-denominated trading from London to inside the Eurozone (one report warned that this could lead to the loss of 232,000 jobs in the City).
Source:
Brexit and the City: a 10-point reality
So far it seems about 7,000 jobs have moved, along with £1 Trillion in assets. I never said all jobs would move, but those related to Eurozone. Thats about 3% of the workforce, with the expectation of a soft Brexit up to now. If it really is a hard-Brexit, and there is regulatory divergence and a loss of equivalency, expect this to increase.
Yes, today lots of transactions are centered in London. The great thing about capital is that it flows. It moves from bad ideas to good. For proof, just look at Somerset Capital Management moving funds from London to Dublin post Brexit and the estimated £7m that Rees-Mogg made from that.
That's the amazing thing about the capital markets. Also, the capital isn't in London, it is brokered through London. London's position is most certainly not unassailable. But please do continue to think it is - nothing makes competition easier than unfounded hubris.
The European market is huge compared to the UK market, and so it has different capital requirements. Expecting London's role in this to remain unchanged in the event of a hard Brexit is very naive. But again, please continue to hold these views - hubris and naivety go together like Roast Beef with Yorkshire Puddings.
The city knows this - that's why they were looking for clarity from the UK government for almost 3 years. That's why London voted to remain.
London will also have to continue to compete with Tokyo and New York, whilst losing market opportunities. Now it will also have to compete with growing financial services sectors in Dublin, Frankfurt, Milan, Paris to which it will continue to lose Eurozone transactions.