For some in the room, it was a moment of déjà vu. In 2016, Michael Gove, then justice secretary, entered the Tory leadership race in an eleventh-hour about-turn that saw him quit as Boris Johnson’s campaign director in an attempt to secure the top job for himself.

Two years later, with the scars barely healed, Mr Gove made another surprise intervention, this time at a crucial Cabinet summit chaired by Theresa May, the Remain-supporting Prime Minister appointed to the role after his elimination from the contest.

Speaking in turn during a formal Cabinet session in the grand parlour at Chequers, the Prime Minister’s country retreat, Mr Gove, who had helped lead the official Leave campaign, insisted that Mrs May’s proposed agreement for a future trading relationship with the EU was the best realistic option for the Government. He said he had reached the conclusion as a result of the combined factors of the Government’s tiny Commons majority, the refusal of Brussels to budge on previous offers, and the fact that planning for a “no deal” outcome was found wanting.

Boris Johnson, the Foreign Secretary, and David Davis, the Brexit Secretary, were convinced that the plan, which involved the UK acting as a tax collector for the EU and a “common rule book” with Brussels on industrial goods and agricultural products, breached key pledges made to voters both during the referendum campaign and subsequently by the Government.