The City will shrink if the UK crashes out of the European Union without a trading deal, senior finance executives warn, as the EU is told to prep for a no-deal Brexit.

Of 90 senior managers at UK-based financial firms polled by Big Four accounting firm EY, 96% said that entering into Brexit on 1 January without agreeing a bespoke trading relationship with the EU would cause the UK financial services industry to shrink “marginally” or “significantly”.