Boris Johnson allegedly joked "f*** the Americans" over calls to back Rishi Sunak's Brexit agreement to ease relations with the White House.
Claims of the ex-Prime Minister's four-letter tirade came as his successor Mr Sunak battled to get a new agreement on the Northern Ireland Protocol over the line.
Mr Johnson, who used his final No10 speech to urge his successor to "stay close the Americans", reportedly made the remark in a private discussion in the Commons chamber.
