Michael Gove has told the Prime Minister to stand down, as more ministers continue to submit their resignation letters.
The Levelling-Up Secretary, who is usually quick to back Mr Johnson was notably absent from Prime Ministers Questions this afternoon.
Mr Gove told Mr Johnson to quit when he was helping the PM prepare for PMQs, the Mail initially reported.
Multiple departmental sources had told the Mirror Mr Gove was "out the door", but a source close to Mr Gove denied these claims, insisting he was still working within the department.
But the source did not deny Mr Gove had urged the PM to quit.
It came as five prominent Tory ministers wrote to the Prime Minister resigning and telling him to "step aside" in a single letter.
Kemi Badenoch, Neil O'Brien, Alex Burghart, Lee Rowley and Julia Lopez brought the total number of people resigning from government to 26 - including 14 ministers - since 6pm yesterday.
Seconds later Mims Davies resigned as Employment Minister, followed by Rachel Maclean quitting her Home Office role pushing the tally to 28.
It comes after former Health Secretary Sajid Javid warned Tory cabinet ministers "not doing something is an active decision" as he pulled apart Boris Johnson's leadership in the Commons.
Ms Davies said she was quitting with a “very heavy heart” but she had become “increasingly concerned” in recent months about “your Premiership, those around you and our great party’s direction and what we truly stand for”.
She added: “I have truly battled with coming to this decision because I am deeply committed to my role and i feel that the government must continue to function and above all deliver for our people.
“However, I feel now the great work we are doing in my government and many others is utterly overshadowed by what has unfolded from the heart of the government in Downing Street.”
The wave of resignations come as Mr Johnson faces a grilling in the Commons as he faces the Liaison Committee.
Mr Johnson appeared to face MPs accompanied by Downing Street's director of communications Guto Harri.
The Prime Minister refused to deny Michael Gove came to him this morning and told him to quit.
He said: “I think I said earlier I’m here to talk about what government is doing, I’m not going to give a running commentary on political events.”
Labour MP Darren Jones asked him: “Prime Minister, how’s your week going?”
Mr Johnson replied: “Terrific!”
During PMQs, Mr Johnson said he would "keep going" and fight another confidence vote despite Rishi Sunak, Sajid Javid and his Solicitor General all resigning last night.
Between 6pm on Tuesday and 3.15pm on Wednesday 28 MPs resigned from the government - 15 ministers, 10 parliamentary private secretaries, two trade envoys and one Tory vice chair.
Backbench MPs across the spectrum, from moderate ex-ministers Chris Skidmore and Nick Gibb to culture war Red Wallers Jonathan Gullis, Tom Hunt and Lee Anderson, have also charged over the top.
The former Constitution Minister wrote: “The Prime Minister has not been truthful. This is an extremely grave situation.”