More than 200 MPs support a motion of no confidence on House of Commons speaker John Bercow, according to the Tory MP trying to unseat him.
Southend MP James Duddridge tabled a motion decrying the speaker last week, and has today told City A.M. he is confident of widespread support.
A vote has yet to be scheduled by the House of Commons authorities, as parliament is still in recess, but with MPs due to return on Monday, Duddridge said a ballot could see "over 200" reject Bercow, with a large number also abstaining.
"Realistically, [Bercow] could get a majority of the vote from a minority of parliament, but how tenable is that?" Duddridge said.
Bercow's predecessor Michael Martin stepped down in the face of repeated questioning in the House of Commons and an Early Day Motion signed by just 22 MPs.
That rebellion was spearheaded by then-Conservative MP Douglas Carswell, now of Ukip, although Carswell has distanced himself from any effort to unseat Bercow, writing on his personal blog: "There are much more important battles to fight."
Duddridge tabled his motion in response to Bercow's controversial intervention over a state visit by US President Donald Trump.
Since then, it has emerged that Bercow voted Remain in the EU referendum, and bemoaned Labour's inability to make a stronger case against Brexit.
And yesterday, more footage was revealed of the speaker describing the idea of a second referendum as "for the birds", months before it was debated by MPs as part of the Article 50 Bill.
"That is such a live issue. It was a major amendment on last week's bill and the speaker of the house had already given a view," Duddridge said, arguing that Bercow's stated positions undermined his impartiality for responsibilities like grouping amendments on Bills, and setting the time allowed for debate.
"His position is totally untenable," the Tory MP said.
Downing Street sources have made clear that Prime Minister Theresa May will not intervene to protect Bercow's position, telling City A.M. that May considered the furore “a House matter”, and adding: “Normal convention is that House matters are a free vote.”