Mrs May has repeatedly claimed she will stay on as Prime Minister after Brexit, arguing she is “not a quitter”.
But following a chaotic Cabinet reshuffle which made her the target of criticism from both Labour and Conservative MPs, her own ministers have warned she will face a rebellion if she attempts to remain in office after Brexit.
Speaking to the Sunday Times, one serving minister said: “The reshuffle has significantly reduced the prime minister’s time in office.
“People are realising that she won’t go of her own accord and will have to be forced out.”
Another added: “Most of my colleagues still don’t think Theresa is serious about fighting the next election.
“When they realise she is deadly serious they will see we cannot continue to indulge the serial disasters like last week.”
It comes after some Westminster insiders have claimed the reshuffle was in fact a clever play to consolidate power.
One senior Tory claimed the subtle reconfiguration of her front bench was a bid to “neutralise” ambitious MPs, moving up and coming ministers who disagree with her policies to different departments instead of doling out promotions or demotions.
Labour and Conservative MPs alike hit out at the PM’s reshuffle, claiming it made her look unable to reign in powerful forces in her own Cabinet.
Secretary for Health and Social Care Jeremy Hunt had initially been tipped to be moved from his position – but instead convinced the PM to keep him in place with an even wider remit than before.
Meanwhile Justine Greening, who had a terse relationship with the PM during her time as Education Secretary, stepped down from the Cabinet after being offered a position in the Department of Work and Pensions.
However despite conflict in the party over the reshuffle, Mrs May’s predecessor David Cameron has reportedly claimed there is no chance the Prime Minister will step down.
Instead the former PM is believed to have claimed Mrs May will cling to power until the bitter end like Gordon Brown, instead of bowing out like himself or Tony Blair.
A friend of Mr Cameron told the Times: “David was suggesting the idea she retires voluntarily seemed implausible”.
Robert Goodwill, who lost his job in the education department during the reshuffle, claimed the meeting with Mrs May was “rather awkward”.
He said: “The meeting with Theresa was shorter and actually rather awkward as the PM and I both started out as candidates in the northeast at the 1992 general election.
“We know each other well, although I wouldn’t say we were close.
“I actually butted in to say I knew why she had called me in and that I quite understood the situation.
“She seemed to be more upset than I was and we parted with a warm handshake.”