Liz Truss is facing growing pressure from within her own party to resign, as Conservative MPs step up their plots to oust her from office.
Senior Tory MP Crispin Blunt on Sunday became the first to break cover and publicly call for her to go.
He told Channel 4's Andrew Neil Show that the prime minister cannot survive the current crisis.
"I think the game is up and it's now a question as to how the succession is managed," he said.
He called for her to be replaced by a leadership team that encompassed Rishi Sunak, Penny Mordaunt and Ms Truss’s new chancellor Jeremy Hunt.
Asked how his party would get rid of her, he said: "If there is such a weight of opinion in the parliamentary party that we have to have a change, then it will be effected.
"Exactly how it is done and exactly under what mechanism ... but it will happen."
Another senior Tory MP, former minister Mark Garnier, also increased the pressure on Ms Truss, saying she was “in office but not in power”.
Asked if she could stay in No 10, Alicia Kearns, the new chair of the Commons Foreign Affairs Committee, told Times Radio: “It’s difficult”.
And former chief whip Andrew Mitchell, an ally of Jeremy Hunt, told the BBC’s World this Weekend: “We’ve got to see what happens in the next few days. If she cannot do the job … I’m afraid that she will go.”
Former chancellor George Osborne said that Ms Truss would likely be gone “before Christmas”.
Behind the scenes, MPs are actively coming up with ways to remove the prime minister from office in a bid to restore the party’s economic credibility and protect it from possible wipeout in parts of the country at the next general election. A number of MPs are expected to hold crisis talks at a dinner on Monday evening.
The Thatcherite group Conservative Way Forward is planning a meeting this week to discuss the crisis.
Leaked messages, seen by news site Tortoise, show former Brexit secretary David Frost telling colleagues "things look bleak".
