Boris Johnson is under growing pressure to resign, after more Conservatives went public with criticism in the wake of the Sue Gray report into partygate.
It takes 54 Tory MPs to formally submit a letter for a no confidence vote in Johnson to be triggered.
Jeremy Wright, the former attorney general, said on Monday that the lockdown breaking scandal had done “lasting damage”.
He hit out at the “contemptuous attitude” shown by people in Downing Street who chose to break the rules. “I have therefore, with regret, concluded that, for the good of this and future governments, the prime minister should resign,” he said.
Carshalton and Wallington MP Elliot Colburn, who was only elected in 2019, also called today for Johnson to step down and said he had sent in a letter.
In a letter to constituents seen by the Daily Telegraph, Nickie Aiken, the MP for Cities of London and Westminster, said Johnson should submit himself to a confidence vote to end “speculation” over his leadership.
Dan Poulter, the MP for Central Suffolk and North Ipswich, said Johnson’s claim that no rules had been broken “lack credibility”.
According to Sky News he said “to mislead parliament cannot be tolerated” and “a minister who knowingly misleads parliament should resign”.
Andrew Bridgen, the MP for North West Leicestershire, who had previously submitted a letter but withdrew it when the war in Ukraine began, has resubmitted it, according to The Guardian.
So far 26 MPs have confirmed they have submitted a letter of no confidence. But the number could be higher, as there is no requirement for them to make it public.
Sir Graham Brady, chairman of the 1922 Committee of backbench Tories, is the only person who knows the number of letters that have been sent in.
It is widely expected in Westminster that Brady would wait until parliament returns from the current recess next Monday, after the Queen’s Jubilee celebrations, before revealing whether the threshold had been met.
Johnson has also plunged to the bottom of the ConservativeHome cabinet rankings, a league table voted on by party members.
It comes as No.10 failed to deny a report that Carrie Johnson hosted a second party in the Downing Street flat, where she and her husband live, on the day of the prime minister’s 56th birthday.