Tory plotters are tapping up 70 MPs in a bid to topple Liz Truss over fears she is trashing the economy.
Senior Conservatives say that is the number needed for their backbench shop steward Sir Graham Brady to go to the PM to tell her she must consider her position.
One plotting MP said: “A flurry of no-confidence letters into Sir Graham would be enough to force him to act.
“We know this is the nuclear option so soon after the last leadership contest but we must think of the best interests of the country.”
The warning came as tens of thousands of people protested in dozens of cities and towns over the latest jump in power bills.
Last week the pound tanked to a record low against the US dollar of $1.03, although it has rallied since.
And the Bank of England had to step in to save pension pots after Chancellor Kwasi Kwarteng ’s £45billion of unfunded mini-budget tax cuts.
As the Sunday People first revealed, 12 letters of no confidence went in as soon as Ms Truss became PM 27 days ago.
But under the rules of the powerful 1922 Committee of backbench Tory MPs she could not face a confidence vote until a year after taking office – even if the number of letters reached the 54 needed to trigger a vote.
Now senior Tories say that if 70 letters go in, the 1922 chair Sir Graham will have to warn Ms Truss he would be calling a meeting of his committee executive to decide if the rules need to be changed.
But he cannot do that until October 18 when a new 1922 executive is formed after the departure of vice-chair Nusrat Ghani to become industry minister.
Boris Johnson ’s former aide Dominic Cummings predicted: “Truss is in a flat spin and won’t recover.
“The only thing going for her is she doesn’t have to face someone like Barack Obama or Bill Clinton.
“But Truss is so bad even dud Keir Starmer can win.”
Even Larry the Downing Street cat turned his back on Ms Truss today after she tried to stroke him while greeting Danish Prime Minster Mette Frederiksen at No10.
Financial markets shivered because the Chancellor refused to publish Office of Budget Responsibility forecasts for his spending.
The OBR will now report to Mr Kwarteng on Friday but the Chancellor insists the details will not be revealed until November 23 when he makes his next financial statement.
MPs say that is not good enough and at least a summary must be published if another run on the pound is to be avoided.
Ian Mulheirn, chief economist at the Tony Blair Institute, said: “The OBR is likely to show that he blew the Government’s financial rules out of the water.
"And the deficit will pile more pain on to the housing market.”
That leaves the PM with the options of U-turning on abolishing the 45% top tax rate or savage cuts.
Mr Mulheirn added: “Cutting public services going into winter with the NHS in crisis and public sector workers striking would be suicidal. The PM must accept political reality and walk back on tax cuts.”
But Tories are furious that Ms Truss has lost the confidence of the markets so soon.
Former Tory minister Sir Alan Duncan said today the mini-budget had been a colossal disaster.
He told GB News: “The inevitable consequence is that people are going to pay more because interest rates are going up and the pound is under strain.”
Former Treasury Secretary David Mellor said: “This is a disaster for the Conservative Party. I can’t imagine how a new PM and Chancellor could have made such a mess of it.”
TUC’s Kate Bell said: “This budget must be reversed.”
Alastair Douglas of TotallyMoney said 20 million people now cannot access credit. He added: “Unless they are to walk into the arms of loan sharks, we need to establish a credit market.”
