Tory Brexiters have declared “open season” on trying to oust Theresa May as she faced an angry backlash over her Brexit talks with Jeremy Corbyn.

One backbencher warned that if the Prime Minister continued with them, she risked being “forced out of office”.

However, a bid by some MPs for a so-called "indicative vote” - a secret poll to guage the mood of the party – was ruled out of order at a meeting of the party’s backbench 1922 committee.

Essex Brexiteer James Duddridge said calls for such a vote had been rejected for now but added: "The indication is that it’s open season; put your letters in and Graham Brady[the committee Chairman] will go and see the PM when it’s 50 per cent plus one."

However, some Tory MPs dismissed the idea. Dorset MP Simon Hoare said: "It was raised as an idea and dismissed as an option."

In December, Mrs May won a confidence vote although a third of MPs voted against her. Technically, however, she cannot be challenged for a year from the date of the contest.

Following her decision to “reach out” to the Labour leader to try to find a Brexit compromise, the PM lost two more ministers, who resigned over her approach to Britain’s withdrawal from the EU. This brought the total number of Government departures in the last few days to seven.

The first to go on Wednesday morning was Nigel Adams, the Wales minister and whip, who resigned saying Mrs May had made a "grave error" by reaching out to Mr Corbyn.

Hours later, Chris Heaton-Harris, the Brexit minister tasked with contingency planning for a no-deal outcome, quit his post, insisting the UK should have left the EU on March 29 as scheduled.

In a letter to the PM the Northamptonshire MP wrote: "I simply cannot support any further extension to Article 50."

Later, Conservative Brexiteer Mark Francois declared: "Jeremy Corbyn is not our friend; he is our opponent. We've spent two years calling him a great threat to our country, which he is."

The Essex MP went on: "My party is already split because very many Conservative MPs are incandescent with what the Prime Minister has done. They're not now talking about the deal, they're talking about what happens to the Prime Minister.

"If she carries on talking to Jeremy Corbyn, there's a risk she'll be forced out of office," added Mr Francois.

But Clare Perry, the Business Minister Claire Perry, described her colleague as being “very angry about Brexit for a very long time”.

She noted: “Mark and his friends tried hard to defenestrate the Prime Minister a while ago and under the terms of our party there is not another opportunity to do so.”

Last week, Mrs May made clear she would step down once the first part of the Brexit process was complete, raising the prospect of a possible leadership challenge in late spring or early summer.

During PMQs, she came under sustained fire from her own MPs.

Lee Rowley, representing North East Derbyshire, pointed out that last week his party leader had said "the biggest threat to our standing in the world, to our defence, and to our economy" was Mr Corbyn. He asked the PM: "In her judgement, what now qualifies him for involvement in Brexit?"

Mrs May replied by stressing how "every member of this House is involved in Brexit".

She explained: “The public want us to work across this House to find a solution that delivers on Brexit, delivers on the referendum, and gives people their faith the politicians have done what they asked and actually delivered for them."

Lincolnshire Tory Caroline Johnson, a normally loyal backbencher, asked her party leader: "If it comes to the point when we have to balance the risk of a no-deal Brexit versus the risk of letting down the country and ushering in a Marxist, anti-Semite-led government, what does she think, at that point, is the lowest risk?"

The PM replied that the Government must deliver Brexit as soon as possible and, in doing so, it made sure “we are delivering on the result of the referendum".