London’s stock exchanges are under pressure from UK regulators to put their no-deal Brexit plans on hold, amid rising political concerns that billions of euros in trading could be about to flood out of the City.

Fears are mounting that the UK is hurtling towards a no-deal Brexit as Theresa May, the UK prime minister, has been unable to seal parliamentary approval for her withdrawal agreement with the European Union, and lawmakers have been unable to put forward credible alternatives.