Update 6.57pm: Boris Johnson has dramatically quit as foreign secretary, complaining that Theresa May’s plan for Brexit would leave the UK a “colony” of the European Union.
In a scathing resignation letter to the Prime Minister, Mr Johnson said that, under her leadership, the UK was “heading for a semi-Brexit”, with the dream of an outward-looking global Britain “dying, suffocated by needless self-doubt”.
Mr Johnson shock departure was the second resignation of a Cabinet “big beast” in less than 24 hours, after Brexit secretary David Davis walked out late on Sunday.
Brexit minister Steve Baker also left the Government.
Both Mr Johnson and Mr Davis had signed up on Friday to Mrs May’s blueprint for Brexit at an all-day summit at Chequers which the Prime Minister believed had secured Cabinet unity behind her proposals.
But her administration was thrown into disarray within 48 hours, as first Mr Davis and then Mr Johnson said that they could not commit themselves to promote the plans under the doctrine of collective responsibility.
Mr Johnson wrote: “On Friday, I acknowledged that my side of the argument were too few to prevail and congratulated you on at least reaching a Cabinet decision on the way forward. “As I said then, the Government now has a song to sing.
“The trouble is that I have practised the words over the weekend and I find they stick in the throat.
“We must have collective responsibility.
“Since I cannot in all conscience champion these proposals, I have sadly concluded that I must go.”