Nadine Dorries has called for Liz Truss to call a general election after accusing her of reneging on a series of policies put in place when Boris Johnson was prime minister.
Dorries, one of Truss's earliest and most vocal supporters during the summer's leadership campaign against Rishi Sunak, revealed her "dismay" at Truss's performance since entering Number 10.
On Monday, Truss and chancellor Kwasi Kwarteng buckled in the face of widespread criticism from the public and Tory MPs and axed her plans to abolish the top rate of income tax that would benefit the most wealthy.
And later, Dorries applied more pressure with criticism of other steps taken by Truss, tweeting: "Widespread dismay at the fact that 3 years of work has effectively been put on hold. No one asked for this.
"C4 sale, online safety, BBC licence feee [sic] review - all signed off by cabinet all ready to go, all stopped."
"If Liz wants a whole new mandate, she must take to the country."
Former ally Dorries is just one of a number of senior Tories to criticise Truss's performance since she became PM less than a month ago.
Last week a former Tory minister MP told Sky News the new Prime Minister is "f*****" and the party were already looking to bring her down following the disastrous mini-budget on 23 September.
The unnamed MP said: "They are already putting letters in as think she will crash the economy. The tax cuts don’t matter as all noise anyway - mainly reversing back to the status quo this year.
"The issue is government fiscal policy is opposite to Bank of England monetary policy - so they are fighting each other. What Kwasi [Kwarteng] gives, the Bank takes away."
Another Tory MP told the broadcaster that Friday's announcement - which included reversing a 1.25% hike in National Insurance - had been a "s***show".
They said they weren’t aware of any coordinated plan to vote down government legislation, but added they would not rule it out.
On Monday morning Truss and Kwarteng abandoned their plan to abolish the top rate of income tax.
The pair had planned to scrap the 45% rate on earnings over £150,000 in a move to be paid for by borrowing. But despite defending the policy for more than a week despite widespread criticism from fellow party members as well as financial experts, the proposal was reversed on Monday morning in an embarrassing U-turn.
Dorries' call for an election came as Labour pushed further ahead in the polls.
Last week, a YouGov/Times poll placed Labour 33 points ahead of the Conservatives, believed to be the largest lead for Labour in any recorded poll since 1998, when the-then PM Tony Blair was enjoying his "honeymoon period".
By Monday lunchtime almost half a million people had signed a petition calling for a general election. The petition must now be considered for debate in Parliament.