Boris Johnson's Chief Whip broke cover on Saturday night to deny incendiary claims by Nusrat Ghani, a 1922 Committee vice-chairman, that a whip said her “Muslimness” was raised at a meeting that led to her sacking in a 2020 reshuffle.
Following allegations by other MPs of bullying by party whips, Ms Ghani said that, after her dismissal as transport minister, she was told of concerns that “I wasn’t loyal to the party as I didn’t do enough to defend the party against Islamophobia allegations”.
On Saturday night, Mark Spencer, the Chief Whip, tweeted: "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.
"These accusations are completely false and I consider them to be defamatory. I have never used those words attributed to me."
The claims are likely to reignite Labour's claims about Islamophobia in the Conservative Party, after an independent report last year found that anti-Muslim sentiment "remains a problem" within the party.
Ms Ghani is the latest member of the 1922 executive to hit out at the party's leadership, at a time when the committee could be days away from overseeing a vote of no confidence in Boris Johnson, and has discussed ditching the ban on more than one such vote per year.
William Wragg, her co-vice chairman, was one of the first Tory MPs to call for the Prime Minister to stand down, while Gary Sambrook, one of the 1922's executive secretaries, has said: "I would expect anyone who is found to have broken the law to seriously consider their position in Government, and that includes the Prime Minister."
On Saturday, Labour MP Chris Bryant, who is chairman of the Commons Standards Committee, claimed a dozen Tory MPs had allegedly been blackmailed by Government whips - and even by Boris Johnson himself.
"I have even heard MPs alleging that the Prime Minister himself has been doing this," Mr Bryant told the BBC Radio 4 Today programme.
"What I have said to all of those people is that that is misconduct in public office. The people who should be dealing with such allegations are the police.
"It is illegal. We are meant to operate as MPs without fear or favour. The allocation of taxpayer funding to constituencies should be according to need, not according to the need to keep the Prime Minister in his job.
"The levelling up funds that have been introduced in the last two years are an open opportunity for Government ministers to corruptly hand out money to some MPs and not to others."
A spokesman for Downing Street said that an investigation into the allegations of blackmail would only be launched “if there was any evidence” to support the claims, despite calls from Labour and Tory MPs.
A spokesman for the Prime Minister said: “We’re not aware of any evidence to support what are clearly serious allegations.
“If there was any evidence to support it, it would of course be looked at.”
On Saturday, a government source also accused 2019 intake MPs of hypocrisy over claims that they may release secret recordings of threats made by whips. The source said: "It's a bit ironic that those who have been complaining about being threatened are now threatening to release secretly recorded conversations."
Scotland Yard are planning to meet a leading rebel Conservative next week to discuss claims of threats and blackmail of backbenchers by the government.
A detective Metropolitan Police will meet with Mr Wragg, who first raised the concerns, to discuss the allegations, including the threats to withdraw investments from constituents.
The claims of intimidation comes as Mr Johnson battles to remain in power ahead of the result of senior civil servant Sue Gray's inquiry into allegations of rule-breaking partying during coronavirus restrictions.
The result of her investigation could come next week.