British Prime Minister Theresa May's leadership is understood to be under fresh pressure after Tory MPs spent nearly an hour in a private meeting discussing how to oust her.
The Press Association understands around 50 MPs talked through the ways and means of getting rid of May at a gathering of the European Research Group.
A number of MPs told how they had submitted letters of no confidence to Sir Graham Brady, chairman of the 1922 Committee, and others discussed plans to follow suit.
If 48 letters are handed over a vote of no confidence would be triggered.
Meanwhile, at a dinner with May's senior aides, MPs raised "leadership issues".
Backbenchers told May's chief of staff, Gavin Barwell, the prime minister must "chuck Chequers" over a dinner at No 10.
The latest furore came after former foreign secretary Boris Johnson launched a fresh attack on May's Brexit plan, claiming it would be "substantially worse than the status quo" for British businesses.
Speaking after the No 10 dinner, Tory MP Andrew Bridgen did not deny suggestions the PM would face a coup.
He told ITV News: "I've been told that she will get a full appraisal of comments that were made over the dinner."
Asked if there would be a coup, he replied: "I think we will just have to wait and see.
"I hope that the Prime Minister will take on board what she's heard and chuck Chequers."
Conservative Brexiteer John Baron told ITV: "We were discussing leadership issues."
Downing Street on Tuesday reiterated that Chequers was "the only serious, credible and negotiable plan which is on the table which both delivers on the will of the British people and which prevents the imposition of a hard border in Northern Ireland".
Australian Associated Press