Senior Tory MP Steve Baker has called for Boris Johnson to quit for not obeying the Covid rules he set.
Mr Baker, a committed Christian and renowned rebel Tory, said the chance to forgive the Prime Minister "had really long gone".
The Commons chamber became eerily silent as Mr Baker had spent much of the debate, urging colleagues to exercise forgiveness whilst quoting scriptures from the Bible.
But he suddenly turned and said: "I've been tempted to forgive.
"But I have to say now the possibility of that really has gone. I'm sorry but for not obeying the letter and the spirit, the prime minister must be long gone... The Prime Minister should know the gig's up".
Mr Baker, who was instrumental in ending Theresa May's reign as Prime Minister, said he would back Labour's motion which seeks to refer the PM to the Privileges Committee.
Downing Street had tried to block and delay the motion but made a dramatic U-turn this morning.
Mr Baker's bombshell remarks came shortly after his Tory colleague William Wragg told MPs he had submitted his letter of no confidence to the 1922 Committee in December.
The PM had travelled to India in a bid to forget about his domestic woes and seal a new trade deal with the state.
Mr Wragg told MPs that Tories had been struggling and working in a "toxic atmosphere" because they have been defending the PM.
"We have been working in a toxic atmosphere. There can be few colleagues who are truly enjoying being members of Parliament at the moment."
Mr Baker said the problem he has with Boris Johnson, "having watched what I would say is contrition, beautiful, marvellous contrition", is that it "only lasted as long as it took to get out of the headmaster's study".
He said: "And that's not good enough for me, and it's not good enough for my voters. I'm sorry, it's not.
"And I'm afraid I am now in a position where I have to acknowledge that if the Prime Minister occupied any other office of senior responsibility, if he was a secretary of state, if he was a minister of state, a parliamentary undersecretary, a permanent secretary, a director general, if he was a chief executive of a private company or a board director, he would be long gone.
"The reason that he is not long gone is because removing a sitting prime minister is an extremely grave matter, and goodness knows, people will know, I've had something to do with that, too.
"It's an extremely grave matter and an extremely big decision and it tends to untether history and all of us, all of us should approach such things with reverence and awe and an awareness of the difficulty of doing it and the potential consequences and that's why I've been tempted to forgive.
"But I have to say now, the possibility of that, really, for me, has gone.”