Tory Brexiteer rebels have claimed they are “not far off” reaching the number of MPs needed to trigger a no confidence vote in Theresa May’s leadership.

Steve Baker, the former Brexit minister, said on Friday afternoon it was “imminent”.

The leading member of the European Research Group (ERG) of Brexiteer Tory MPs told BBC’s Politics Live programme that by his count the number was “over 48 with another almost dozen probably on top”.

But he added his estimate would be “inaccurate” as some MPs would have lied to him about whether they had submitted a letter or not. “I think we are close,” he said.

So far, 20 Tory MPs have made public their formal demand for a vote of no confidence. HuffPost UK understands that as of this morning, the 48-letter mark had not been reached.

Mark Francois, another leading Brexiteer backbencher, subtitled his letter with the phrase: “She Just Doesn’t Listen”.

Under the Conservative Party rules, a no confidence vote is triggered once 15% of MPs write letters to the current chair of the party’s backbench 1922 committee, Sir Graham Brady.

To survive, May would need to convince a simple majority of her MPs to back her. If she lost, May would have to stand down as Tory leader and would not be allowed to run in the leadership contest that would take place.

Fresh speculation about a leadership challenge was fuelled on Friday morning as it was revealed all Conservative Party Whips had been ordered to cancel constituency engagements and return to Westminster.

But May received a boost this morning when Michael Gove decided not to resign as Environment Secretary.

But he reportedly turned down the offer to be made Brexit Secretary, and pointedly refused to say he backed the current Brexit agreement, adding the focus should be on “getting the right deal in the future”.

International Trade Secretary Liam Fox also this morning gave the PM his backing. “What we need now is stability,” he said.

The PM defended her position this morning as she took questions from members of the public on LBC’s morning radio call-in show.

But she could not guarantee she had the support of the DUP, who prop up her minority government. “When this vote comes back every individual MP will decide how they will vote, whether they are DUP, Conservative, Labour, all parties within the House of Commons,” she said.

The Prime Minister was rocked by the resignations of Brexit Secretary Dominic Raab and Work and Pensions Secretary Esther McVey yesterday, both of whom resigned from Cabinet just hours after May presented the draft Brexit deal for the first time.

May’s political future hung in the balance following the publication of her 585-page agreement, which will provide the basis of a legally binding treaty for the UK’s exit from the EU.

It covers the future rights of EU citizens living in the UK and UK nationals in the EU, the UK’s £39bn “divorce” settlement, as well as protocols on Gibraltar and the UK sovereign base areas in Cyprus.

It also provides for a transition period after the UK leaves in March 2019 running to the end of 2020, with the option of a one-off extension if more time is needed to conclude an agreement on the future relationship.

Crucially it also covers the so-called “backstop” intended to ensure there is no return to the hard border between Northern Ireland and the Republic if negotiations on the future relationship have still not been completed.