Theresa May is facing mounting pressure to resign after Commons leader Andrea Leadsom quit her role.
Ms Leadsom resigned with a "heavy heart" last night, saying she no longer believes the government's approach will deliver on the referendum result to leave the European Union.
The Prime Minister, writing in reply, disagreed with the ex-minister's assessment, but said she was sorry to lose someone of Ms Leadsom's "passion, drive and sincerity".
The move has increased pressure on the Prime Minister to resign as Conservative leader, with the 1922 Committee meeting yesterday, reportedly to discuss ways to eject her.
According to the Committee chair, Sir Graham Brady, they discussed "all sorts of things" in the meeting.
The Committee's executive had been expected to consider a rule change to allow another attempt to force Mrs May out, and joint executive secretary Nigel Evans telling talkRADIO yesterday that he would be "pushing very hard" to oust the Prime Minister.
"I will be pushing very hard for a vote on a rule change in order that MPs have the opportunity themselves to express whether or not they have confidence in the Prime Minister," he told talkRADIO's Julia Hartley-Brewer ahead of the meeting.
Mrs May had agreed to set out a timetable for a leadership contest after a vote on her Brexit deal in early June, but the deadline appears to have been brought forward with the announcement that she will meet Sir Graham the day after polling day for the European elections.