Culture Secretary Nadine Dorries has blamed Rishi Sunak for the "ruthless coup" which ousted Boris Johnson from No10.
Ms Dorries, a staunch Johnson loyalist, renewed her attacks on the Tory leadership hopeful, who she named as a ringleader in removing the Prime Minister from Downing Street.
In a series of outspoken interviews - one of which was interrupted by someone shouting at a cameraman - Ms Dorries tore into Mr Sunak and said she was "bitterly disappointed" by Mr Johnson's resignation.
However she insisted that outgoing PM was not supporting a grassroots push to get his name on the leadership ballot.
The Tory leadership contest has descended into open warfare with Liz Truss and Rishi Sunak's camps trading barbs and trashing each other's records in Government.
In a sign of the acrimony, Ms Dorries claimed Mr Sunak had partly orchestrated the PM's downfall and doubled down on her criticisms of his expensive taste.
She told BBC Radio 4's Today programme: "I am bitterly disappointed that Boris Johnson was removed by a ruthless coup, as he was, led largely by Rishi Sunak."
The Culture Secretary, who is backing Ms Truss, railed against the ousting of a "great leader" and said it had "unleashed the hounds of hell" in a round of interviews.
"Removing a sitting Prime Minister who won us an 80-seat majority less than three years ago, who took us through Covid and led the world in the response to the war in Ukraine - defenestrating that Prime Minister was never going to be a clean or easy thing for anyone to do.
"It was always going to have repercussions. I think I said at the very beginning we kind of unleashed the hounds of hell in doing that."
Mr Sunak's shock resignation - minutes after Health Secretary Sajid Javid also quit - triggered an avalanche of ministerial departures, eventually forcing the PM to admit defeat.
Angry Johnson allies are said to blame Mr Sunak for the PM's departure, with reports of efforts to install "Anyone but Rishi" in Downing Street.
Mr Javid, who was knocked out of the leadership contest by MPs, denied at the time that the campaigns were coordinated.
Ms Dorries was unapologetic about her recent criticism of Mr Sunak's expensive taste in clothing, which caused one exasperated MP to tweet "FFS Nadine!".
Asked about her comments, she said: "Judgment is a huge issue. We are facing a cost-of-living crisis."
She said there was no barrier to someone wealthy becoming prime minister but "it's about judgment and it's about who voters can relate to and who voters can relate to and who voters think have walked in their shoes and can understand their lives".
But when asked about her own expensive taste in clothes, she said: "I am not and never will be running to be Prime Minister."
Ms Dorries also said Mr Johnson had told her that he didn't support efforts by party faithful to get him onto the ballot for the leadership.
She said the PM told her "'Tell them to stop, it's not right' - they were his words, his exact words".
Rishi Sunak's team declined to comment.
