At least one Tory MP demanded the leader resigns while another said she would not more than six months after a disastrous campaign.
Furious members blamed the social care “ dementia tax ” fiasco for the defeat, while others pointed to the PM’s thirst to bring back fox hunting.
Anna Soubry, whose majority in Broxtowe, Notts, was cut from 4,287 to just 863, called on Mrs May to quit.
The ex-Business Minister said: “She is in a difficult place. She is a remarkable and very talented woman and she doesn’t shy from difficult decisions.
“But she now has to consider her position.”
The PM “put her mark on this campaign” rather than the party, said Ms Soubry. She added: “It was a dreadful night.
“I’ve lost some excellent and remarkable friends — proper, sound, moderate Conservatives.
“This is a very bad moment for the party. We need to take stock — and our leader needs to take stock as well.” The manifesto U-turn on a social care cap was labelled a “serious blow” to Mrs May’s credibility.
Ms Soubry added: “It did not make her look the strong and stable Prime Minister and leader she had said she was.”
Meanwhile, Tory MP Heidi Allen said of Mrs May’s decision to carry on: “It feels like she’s almost not aware of what has happened in the last 24 hours. You can’t simply just put your head down and say, ‘We get on with it’.”
When asked how long she gave the PM, Ms Allen replied: “I don’t see any more than six months.”
Nigel Evans, another Tory MP, also blamed the social care policy for the disaster and called for a change in Mrs May’s leadership team.
He said: “Theresa May, I’m certain, will want to explain how there is going to be a change in the way we are going to do things. Had some Cabinet ministers seen that policy beforehand, surely that never would have featured in our manifesto.
“Never have I seen a very successful campaign, up until that point, being hijacked by ourselves. From then on, it was an absolute disaster.” Mr Evans said the Tory backbench 1922 Committee would discuss her leadership.
Mrs May angered moderate Tories with her desire to scrap the fox hunting ban. The Mirror revealed a plot to bring back the bloodsport — and the PM confirmed she wanted a free vote on a return to hunting.
Sarah Wollaston, re-elected in Totnes but with her majority cut by almost 5,000, said: “Fox hunting and changes to social care were turning points in how people felt about the PM. Hope we never again have such a negative campaign.”
A top Tory official in the Midlands blasted the election run-in.
Sally Brealey, Broxtowe Conservatives’ deputy chairwoman, said: “We ran an arrogant campaign, more about scaring people than shouting about our achievements. We have learnt nothing from Clinton or Brexit that people vote for positivity. Oh, and don’t get me started on fox hunting.”
A Government minister, who did not want to be named, called for Conservative Party chairman Sir Patrick McLoughlin to resign, saying the manifesto was “ill-thought out”.
Boris Johnson was the immediate favourite to take over from Theresa May if she is forced to step down.
The Foreign Secretary was poised to run for the top job last June in the aftermath of the Brexit referendum.
But Mr Johnson, 52, had to abandon the bid after fellow Brexiteer Michael Gove betrayed him. He was the 7/4 favourite with Ladbrokes but he is seen as a maverick and Tory MPs distrust him.
Potential rivals include Brexit Secretary David Davis, 68, quoted at 4/1, who will spearhead negotiations with the EU. The ex-SAS reservist was favourite for the role in 2005 but lost to David Cameron.
Home Secretary Amber Rudd, 53, had been tipped as Mrs May’s favoured choice as successor but then her majority in Hastings and Rye was slashed from 4,796 to 346.
However, her handling of terror attacks has been praised. She was 6/1 to be the next leader.
Chancellor Philip Hammond, 61, was quoted at odds of 8/1. He has held a string of Cabinet posts before being sent to the Treasury last July.
But his Budget in March when he tried to slap a national insurance hike on self-employed workers – breaching a 2015 Tory manifesto pledge – damaged his “brand”. (Mirror)