It was just five days after Boris Johnson had entered Downing Street when the six-member Brexit “war cabinet” met for the first time around the Cabinet table to set out a strategy for abolishing the Irish backstop.

Known as the Exit Strategy or “XS” committee, it comprised the Prime Minister and five key Cabinet ministers involved in delivering Brexit “do or die”.

According to highly-placed sources, the meeting on July 29 discussed the diplomatic and tactical approach to getting rid of the backstop, something Mr Johnson said was the minimum requirement for a Brexit deal in his first statement to the Commons on July 25.

The plan, set out in a presentation entitled “Approach to engagement with the EU on renegotiation”, backed by David Frost, Mr Johnson’s Europe adviser, was to “run down the clock” with the EU closer and closer to the no deal cliff edge. Senior sources say the strategy was adopted as formal policy, raising the question in Whitehall and Brussels of whether or not the Government was actually serious about reaching a new deal.

Mr Johnson spoke publicly about the “abundant” technical fixes for the Irish border and said “no deal” was a “million-to-one”, but in private he received very different messages.