A Kent MP says the Prime Minister has "an eccentric relationship with the truth" following an apology in the Commons yesterday.
Addressing MPs, Boris Johnson insisted he did not know he was breaking his own coronavirus rules after he was fined by police for attending a Downing Street birthday party.
The North Thanet MP Sir Roger Gale has previously said the PM should consider his position if he was found to have misled Parliament over whether he had attended social gatherings at Downing Street.
He has now added that Mr Johnson's position has been "untenable" for a while but waiting for him to resign would be like "wishing for pigs to fly".
He said: "I have a lot of sympathy with the view that Conservative MP Mark Harper expressed that the Prime Minister has an eccentric relationship with the truth, this is true."
However, Sir Roger stands by his previous statements that now is not the time for a leadership election.
He told Sky News: "We are in the middle of a very grave crisis and the last thing we want to do is destabilise the government of the United Kingdom and therefore potentially destabilise the coalition against Putin's criminal war when we are facing such a dire circumstance."
Sir Roger continued: "But, and I suspect this may happen, there are more Metropolitan Police finds and the Sue Gray report is damning, that ground will shift and there is no doubt about that."
Earlier this week the senior Tory suggested a “war cabinet” could be established in place of a leadership contest if the PM resigns or is voted out.
Sir Roger believes this interim administration could be successfully led by the deputy prime minister, Dominic Raab.
The veteran Conservative MP previously submitted a letter of no confidence in the Prime Minister, which he says remains “on the table” as he suggests the PM does not take his role as seriously as he should do.
After attending the 1922 Committee yesterday, Sir Roger said: "I'll be frank, I stayed for three minutes and left – I didn't storm out. I found the tone of the meeting from the very beginning, shall we say very different from the tone in the House of Commons and had gone expecting a serious meeting about serious issues."
He then likened the speech of Mr Johnson to a pantomime performance.
He said: "I didn't expect a lot of bluster and pantomime performance and I'm afraid that's what I heard.
"It seemed to me that my time was better spent doing other things."
However, Sir Roger did add that he has since been told that the tone of the meeting did become more serious with backbench MPs asking more serious questions later on.