Bury South MP Christian Wakeford has said Boris Johnson is "living on borrowed time" as he hit out at the prime minister for "poisoning the Tory Party from top to bottom”.
Mr Wakeford, who became the first elected Tory in the Greater Manchester constituency for more than 20 years in 2019, defected from the Conservatives to Labour on Wednesday.
He later claimed that he was threatened about the loss of a school in his constituency if he did not toe the line.
Writing in the Sunday Mirror, Mr Wakeford said: “Boris Johnson is living on borrowed time. He has poisoned the Tory Party from top to bottom.”
The Bury South MP said the investigation into No 10 by civil servant Sue Gray would show Downing Street was “hosting parties while the rest of us were obeying the rules”.
“The PM attended and then lied about it. He showed no respect for the Queen while she was in mourning for her husband,” Mr Wakeford wrote.
“His behaviour has been an insult not just to Her Majesty but to the whole nation.
“His lack of honesty and integrity has poisoned the once great party he leads.”
Mr Wakeford claimed that the "bully boys at Westminster" told him that he "wouldn’t get a promised new school in Bury South if I voted the wrong way".
"The police are now being asked to investigate allegations that other Tory MPs were blackmailed into putting Boris Johnson’s interests ahead of their own constituents," he said.
Mr Wakeford added he had “too much respect for the people who voted me into Parliament to stay silent in the face of such intimidation”.
The MP also criticised Mr Johnson's plans for levelling up, saying that people in his constituency wanted to see "wealth and opportunity" for the region under a Tory government.
"The Tories have let them down," he said.
"Only Labour with Keir Starmer has a serious plan for levelling up. The Labour Party I joined last week is serious about making Brexit work. There’s no going back into the EU."
He added "moderate, sensible centrists like me no longer have a place" in the party.
It comes amid calls for another inquiry after Tory MP Nusrat Ghani claims was told that she was sacked from her ministerial post because her Muslim faith was “making colleagues uncomfortable”.
Ms Ghani claims when she lost her job as a transport minister in 2020, a government whip told her “Muslimness” had been raised as an issue at a Downing Street meeting to discuss the reshuffle.
In an interview with The Sunday Times, Ms Ghani, the MP for Wealden, said she was shocked when the issue of her background and faith was raised during a meeting in the whips’ office after the mini-reshuffle in February 2020.
“It was like being punched in the stomach. I felt humiliated and powerless,” she told the paper.
Chief whip Mark Spencer said that he was the individual who spoke to Ms Ghani – although he strongly denied using the words claimed.
“To ensure other whips are not drawn into this matter, I am identifying myself as the person Nusrat Ghani MP has made claims about this evening,” he said in a statement posted on Twitter.
“These accusations are completely false and I consider them to be defamatory. I have never used those words attributed to me.”
Education secretary Nadhim Zahawi said there was no place for Islamophobia or any form of racism in the party, and that her allegations must be “investigated properly and racism routed out”.
The senior Tory who first raised the issue of the conduct of the whips’ office, Hazel Grove MP William Wragg, also voiced his support for Ms Ghani.
“Nus is very brave to speak out. I was truly appalled to learn of her experience. She shows such strength and integrity supporting others,” he tweeted.
Mr Wragg is due to discuss his concerns – including claims whips threatened to withhold public funding from the constituencies of MPs calling for Mr Johnson to resign – with a Scotland Yard detective this week.
Deputy PM Dominic Raab has defended the prime minister, saying he “has taken a few hits but he’ll come out fighting”.
Writing in The Sun on Sunday, Mr Raab said: “In less than three years in office, the Prime Minister has faced two of the nation’s biggest challenges in our post-war history: Delivering Brexit and getting us through the worst pandemic in living memory.
“It has not been easy. He has taken some knocks. But the thing about this Prime Minister is that he never stays on the ropes for long.”
Mr Raab said the “culture in No 10 needs to be addressed to meet the standards the public rightly expect” but added the Prime Minister “is in your corner”.
