Theresa May has called for a crisis summit in order to prepare for a ‘no deal’ situation, amid fears the row between Brexiteers and Remainers is undermining negotiations with Brussels.

The prime minister told cabinet ministers on Friday morning to be prepared to meet on September 13 to work out a plan for critical areas not yet covered by disaster plans.

The crisis meeting comes as Dominic Raab risked a Cabinet row with Philip Hammond after questioning the worth of economic forecasts about Brexit , days after the Chancellor warned that no deal could cause major damage.

In an interview with the Sunday Times, the Brexit Secretary said that some projections needed to be treated with ‘a measure of caution’, adding that GDP estimates for 2019 ‘have been revised up.

Mr Hammond was accused of launching a ‘dodgy Project Fear’ on Thursday when he suggested that GDP could fall and borrowing could be around £80 billion a year under a scenario in which Britain resorted to World Trade Organisation (WTO) terms after a no-deal Brexit.