Up to 40 Conservative MPs are now said to be prepared to sign a letter of no confidence in Theresa May.
The number has increased in recent weeks, since the Tory conference after Ms May’s Government has been hit by a series of crises.
If eight more MPs put their name to the letter it would trigger a vote of no confidence which, if lost, would lead to a Conservative leadership contest.
A senior Tory MP told The Independent: “Patience is wearing very thin and in some cases, it has snapped.”
After Ms May’s disastrous conference speech there were said to be around 35 names on the list, precipitating an attempted coup which failed due to insufficient support.
But since then, the sexual harassment scandal, the loss of Sir Michael Fallon and Priti Patel from the cabinet, a severe gaffe by Boris Johnson which led to a British woman facing a longer jail term in Iran and divisions over Brexit have all contributed to fears in the party that Ms May is losing grip.
Under Tory rules 48 MPs would need to sign a letter of no confidence and deliver it to the chair of the backbench 1922 Committee to spark the vote on Ms May’s future.
They said transition arrangements for Britain's exit from the European Union must end on June 30 2021 and urged the Prime Minister to ensure members of her top team fall behind their plans by “clarifying their minds” and called for them to “internalise the logic” they are putting forward, the Mail on Sunday reported.
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