Nadine Dorries launched a scathing attack on Rishi Sunak, branding him a “loser” who is going to lose three key by-elections.
The former culture secretary, who is said she is quitting as a Conservative MP, said the prime minister is “fake”.
And Ms Dorries slammed Mr Sunak as “not a very clever guy”, adding that she is “actually smarter than these guys in No10”.
The Mid Bedfordshire MP said she was quitting “with immediate effect” last Friday after a bust-up with Mr Sunak over Boris Johnson’s resignation honours list.
She had expected to be offered a seat in the House of Lords, but accused Mr Sunak and his aide James Forsyth of concocting a “posh boy” plot to deny her a peerage.
She has since delayed her resignation, insisting she will not quit until she gets answers from Downing Street about why she was not given the peerage.
And, in Ms Dorries’ latest attack on the PM, she predicted he will lose a series of upcoming by-elections to replace her, Mr Johnson and Boris ally Nigel Adams – both of whom also decided to quit last Friday.
In an interview with the Financial Times, Ms Dorries said: “Being underestimated is the story of my life. It works to my advantage every time. Who’s the winner now [after the peerage row]? Because it’s not Rishi Sunak or [his political adviser] James Forsyth. Whose reputation is damaged? It’s not mine.
“Who looks the loser? It’s not me. OK, so I’m not going into the Lords, but I’ve got a lot of things happening in my life that are very productive. Has my reputation been tarnished? Am I seen as the lesser person? Am I going to lose three by-elections?”
She also made the false claim that Mr Johnson was “top of his year” at the University of Oxford, while Mr Sunak “came 200-and-something”.
And she said that, while she was always “quite supportive of Rishi”, he has “behaved in such a way that’s made me think what you see on the surface is all fake”.
Asked whether Mr Johnson would return to frontline politics in the wake of a damning report his conduct as PM, she said “I don’t think so”.
“Why would he come back? Most of the MPs who voted to remove him would rather poke their own eyes out than admit they were wrong,” she added.
And Ms Dorries lashed out at senior Tories including the deputy prime minister Oliver Dowden. Speaking about Mr Dowden’s promotion to the crucial role, she said: “How did that happen? He’s a bloke who can’t even speak at the despatch box without reading notes.”
And, in a stunning change of stance, Ms Dorries said former PM David Cameron was wrong to resign when he did. In the run up to the Brexit referendum, after which he quit, Ms Dorries said Mr Cameron was an “outright liar” and called for him to go.
Her intervention comes days after relations between Mr Johnson and his successor hit rock bottom. Mr Sunak said he had been asked by the former PM to bend the rules on peerages, before Mr Johnson hit back to accuse him of “talking rubbish”.
Ms Dorries was initially set to get a peerage, but rules about sitting MPs being elevated to the House of Lords meant she would have had to agree to resign before being awarded it.
“[Sunak’s team] knew I wouldn’t be on the list, because they hadn’t given me the information to act to ensure that I was . . . I’m actually smarter than these guys in No 10. All they had to do was work with me,” she told the FT.
