Brexit rebels Boris Johnson and David Davis clashed last night over claims they discussed a ‘joint Cabinet walk-out stunt’ that could have brought down Theresa May.

Allies of Mr Johnson said Mr Davis suggested that they should announce they were leaving the Government over Brexit in a co-ordinated double act – but the former Foreign Secretary declined.

But sources close to Mr Davis said it was Mr Johnson who put forward the idea, which the former Brexit Secretary then declined.

The conflicting accounts came after Mr Davis resigned dramatically at midnight last Sunday, followed by Mr Johnson 15 hours later.

The Mail on Sunday has established that Mr Davis phoned several Ministers, including Mr Johnson, on Sunday to tell him he intended to quit. Thereafter, both sides give conflicting accounts of their conversation.

Brexit rebels Boris Johnson and David Davis clashed last night over claims they discussed a ‘joint Cabinet walk-out stunt’ that could have brought down Theresa May

According to allies of Mr Johnson, he told Mr Davis that he had decided to resign the previous day, after refusing to put his name to a newspaper article written for him by Downing Street that endorsed the Brexit deal thrashed out at Chequers on the Friday.

The Johnson camp say Mr Davis suggested a joint resignation with Mr Johnson to maximise the effect, but Mr Johnson declined because he was keen to discuss ‘resignation logistics’ on Monday morning with family and aides. The Davis camp dismiss this version of events as ‘nonsense’ and claim it was ‘the other way round.’

Some Tory MPs say that had the two Cabinet heavyweights resigned together, it would have put much greater pressure on Mrs May.

Their decision to quit separately led some of Mr Davis’s supporters to claim that Mr Johnson had damaged his prospects of becoming Prime Minister by failing to take the initiative, allowing Mr Davis to ‘steal his thunder’.

Sources close to Mr Davis said it was Mr Johnson who put forward the idea, which the former Brexit Secretary then declined

No 10 is now waiting for both men to make their next move.

Mr Davis is due to appear on the BBC’s Andrew Marr Show this morning, while Mr Johnson’s first newspaper column since his resignation appears tomorrow.

It is understood Mr Johnson has not yet decided whether to make a dramatic resignation speech in the Commons before MPs break up for the summer recess on Friday. It is most likely to be straight after Prime Minister’s Questions on Wednesday, if it takes place.

Allies played down rumours that Mr Johnson would use the speech to suggest Mrs May ‘consider her position’ and that Mr Johnson was planning a Jeremy Corbyn-style rally in Sunderland over the summer to outline his vision for a ‘pure Brexit’.

One source said: ‘He is taking the weekend to decide, but his main priority is to move house and plan a holiday.’

The source added that Mr Johnson was considering a big setpiece speech in September, before the EU summit in October that is expected to finalise the deal.

MPs will then vote on whether to accept the deal in what is likely to prove a pivotal moment in the May premiership.