- Monday's leadership vote is "the beginning of the end" for Johnson even if he wins, MPs told Insider.
- Several new names have called for Johnson to go, including possible leadership rival Jeremy Hunt.
- The prime minister could try to fight back by reshuffling his top team, some sources said.
Boris Johnson could be forced out of office within months even if he wins Monday's confidence vote, Conservative MPs believe.
Several backbench MPs told Insider they believed the prime minister would survive the vote, but that it was the end-game for his leadership.
The MPs asked for anonymity to describe the situation. The prime minister's fate is in the hands of his MPs, after Sir Graham Brady, chairman of the 1922 backbench committee, announced enough of the party's MPs had submitted letters of no confidence in Johnson to trigger a vote.
Both rebels and supporters have been canvassing support ahead of the vote, which was scheduled for Monday evening.
Johnson has to secure 180 of a possible 359 votes in the ballot to win. If he loses then the Conservative Party will hold an internal leadership contest, which Johnson could try to win.
He plans to address MPs around 4 p.m., two hours before the vote takes place, according to a notice from Brady.
One Conservative MP said: "I think he'll win but it's the beginning of the end. It's actually far better for everyone if he goes voluntarily."
Another said: "He will win but be gone in six months… It is Theresa May 2.0 [and] she lasted seven months."
It would not be "the end of the campaign" against him, the MP added.
Johnson would win but "ministers won't all back him", another senior backbencher said.
John Penrose, who quit as Johnson's anti-corruption tzar and called for the prime minister to resign on Monday morning, told Sky News: "If he wins a thumping victory that might be different… but as far as anyone can tell, it feels like the beginning of the end.
—John Penrose (@JohnPenroseNews) June 6, 2022
He added: "If it's a sizable rebellion then it's very difficult for him to survive for very long."
However Jacob Rees-Mogg, the minister for Brexit opportunities, signaled that Johnson would fight on. The minister told Sky News that the prime minister would have a mandate if he wins the ballot by just one vote.
"In a democracy, one is enough," Rees-Mogg said. "I think that the idea that there is a barrier different from the absolute barrier is false."
The first day back after the long Platinum Jubilee weekend has seen several other MPs publicly call for Johnson to resign.
Jesse Norman, a former Treasury minister, published an excoriating letter detailing many criticisms of the man he has supported for 15 years.
—Jesse Norman (@Jesse_Norman) June 6, 2022
Jeremy Hunt, a former Cabinet minister, said colleagues should "reflect that the consequence of not changing will be to hand the country to others who do not share those values".
He added: "Today's decision is change or lose. I will be voting for change."
Angela Richardson, who resigned as PPS over partygate, said she would vote no confidence in Johnson.
Dozens of other Tory MPs have publicly backed Johnson, although the ballot will be held in secret.