Would flood out of the UK and into Europe because of Brexit.
However it would appear that, from a Guardian article and it's source ECB communication that banks have absolutely no intention of leaving London and are intending to do the absolute minimum required to allow them to continue to trade Euro trades.
And, of course, lest we forget, the Euro is only 19 of the 27 states left in the EU when the UK leaves. Which puts it pretty much down below China in terms of GDP and lending and financial importance.
There has been talk about the Renmimbi taking over as a reserve currency and that the UK could become, once leaving the EU, the premier centre in the world for Renmimbi clearing and denominated financing. The thought had occurred to me that the banks, especially the non EU banks, have absolutely no intention of leaving London for Paris or Frankfurt and missing the largest ever single expansion in a clearing and lending market.
The tone of the ECB communication comes over to me as concerned. In the end if Banks meet the letter of the law but the EU trades and clearing continues in London, they continue to lose all that lucrative transaction tax the banks don't pay in London.
I suspect we will be seeing a tussle of wills over the next year. Absolutely nothing to do with the Brexit negotiations at state level, but to do with Banks and the ECB going head to head over what the ECB wants and what the Banks are willing to give them....
It is going to be an amusing few months...
Expect the Guardian and the Independent to play it as a weakness of the UK.... As ever in this Brexit situation. However, just like the Government winning every one of its votes in parliament on the Brexit Bill, so far, our banking is stronger than they report; just as is the government.