Conor Burns, a Tory MP and former minister, said he had concerns that “some members” of the Privileges Committee have already “predetermined their view” on whether Boris Johnson misled Parliament over the partygate scandal. 

The Privileges Committee is made up of seven MPs and is chaired by Labour’s Harriet Harman. Critics have questioned the impartiality of Ms Harman after a social media post last year indicated she believed Mr Johnson had misled Parliament.

Mr Burns, an ally of Mr Johnson, told the BBC’s Westminster Hour programme: “Now, the concern that some of us have is that it appears that some members of that committee have predetermined their view. I have real reservations. 

“I rate Harriet Harman highly but she did tweet in April 2022 that if the prime minister, the former prime minister, the now Prime Minister, the former chancellor, admit guilt by which she said was accepting a fixed penalty notice then they are also admitting that they misled the House of Commons. 

“Boris Johnson contests that but it seems to me the person who is now chairing this committee has predetermined that and that causes me a degree of anxiety for parliament’s reputation in handling this with integrity.”

Baroness Chapman, Labour’s shadow Cabinet Office minister, suggested allies of Mr Johnson were trying to “throw sand in the wheels” of the probe.

She told the same programme that she believed Ms Harman will “make sure that this is a fair process”.