Business leaders expressed growing alarm on Thursday as a draft Brexit agreement seen as the only chance of preserving some stability in U.K.-EU trading threatened to unravel, sending stock prices and the pound plunging.

Just 12 hours after British Prime Minister Theresa May announced that her Cabinet had agreed to the terms of the draft agreement, Brexit Minister Dominic Raab and work and pensions minister Esther McVey quit, saying they could not support it.

Their departures and those of other, junior ministers, revived the specter of Britain exiting the European Union without a deal next March, and sent shares in British house builders, retailers and banks tumbling.