Great Yarmouth MP Brandon Lewis is preparing to tell prime minister Boris Johnson to leave Number 10, it has been reported.
A source close to the Northern Ireland secretary has told the PA news agency Mr Lewis believes the prime minister's position "is now untenable".
It comes as a delegation of cabinet ministers get ready to urge Mr Johnson to leave Downing Street, as he haemorrhaged support across the Tory ranks.
Transport secretary Grant Shapps, who was key to the Prime Minister’s fight for survival during partygate, is among those who will demand he quits, sources told the PA news agency.
And Mr Lewis, up to now a long-standing ally of Mr Johnson, is also understood to be part of the group.
More than a dozen ministers resigned as Mr Johnson haemorrhaged support on Wednesday, leaving his position in grave doubt.
The mass resignation of ministers, along with a string of parliamentary aides, came after Rishi Sunak and Sajid Javid quit their cabinet posts on Tuesday evening.
North Norfolk MP Duncan Baker quit his position as parliamentary private secretary on Wednesday, saying he did not "have confidence in the prime minister".
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