A bitter row has broken out about the future of Commons Speaker John Bercow after a Tory MP launched a bid to oust him.
James Duddridge tabled a parliamentary motion of no confidence in the Speaker and predicted he could be "dead in the water" within days if MPs made public their private concerns about Mr Bercow.
But supporters of Mr Bercow rallied behind him, with one Labour MP branding Mr Duddridge's move "utterly ridiculous and self-indulgent".
Former minister Mr Duddridge said he had been "amazed" by the level of support he had received since speaking out about Mr Bercow's critical comments aimed at US president Donald Trump.
The early day motion (EDM) - a way for MPs to register concern about an issue - was tabled as Parliament rose for its February recess, which Mr Duddridge said would give his colleagues time to think about the issue.
He suggested that by the time MPs come back to Westminster on February 20, Mr Bercow may realise his position is "untenable, perhaps even to the point that he doesn't return on the Monday".
Fellow Tory MP Alec Shelbrooke backed the motion, saying that although Mr Trump's "faith-based migrant ban" is "discriminatory" and "wrong", Mr Bercow had "politicised the office of Speaker and his position is untenable".
But Labour MP Jess Phillips dismissed the Speaker's critics as a "load of rich blokes", saying: "Loads of Tories don't like Bercow because he's trying to reform the Commons and make it more representative.
"I will vote to support John Bercow, utterly ridiculous and self-indulgent of MP who will waste all our time on this."
Senior Labour MP Andy Burnham and shadow cabinet ministers Barbara Keeley and Kate Osamor also expressed their support for the Speaker.
SNP MP Tasmina Ahmed-Sheikh told BBC2's Newsnight: "This is a modernising Speaker.
"James Duddridge has mentioned previously that he has an objection to a modernising Speaker, well I think we need to take the House of Commons into the 21st century and take it out of what would seem to be a Hogwarts type of debating society that many Tory MPs want it to be."
Ukip MP Douglas Carswell, whose motion of no confidence led to the downfall of Michael Martin as speaker in 2009, said the move against Mr Bercow was "misguided".
Mr Duddridge would not be drawn on how many MPs he expected to support his motion, but told the Press Association: "I have been amazed at the number of emails, texts saying 'Carry on as you are doing, James, we totally support you'.
"Some of those were quite keen to get actively involved, some were a little bit more happy that someone else was doing it rather than them.
"I have got absolute confidence that a majority of MPs will be in the 'he's not doing a good job and should go' category.
"How many of those will go as far as voting in a vote of no confidence and how many will sign up to an EDM, I genuinely don't know."
In order for a debate to be held on the issue, Parliamentary time would have to be allocated to it, and Mr Duddridge said there were a number of possible ways that could happen.
If the Government refused to allocate time, the issue could be selected for a formal debate through a request to the Backbench Business Committee - or even through a public "Bercow must go" parliamentary petition to trigger a vote.
The row was triggered when Mr Bercow backed MPs who had opposed the prospect of the US president addressing Parliament in Westminster Hall during his state visit later this year.
Mr Bercow said he was "strongly opposed to an address by President Trump in Westminster Hall" and his views had been strengthened by the travel ban.
He added: "If a state visit takes place, that is way beyond and above the pay grade of the Speaker.
"However, as far as this place is concerned, I feel very strongly that our opposition to racism and to sexism, and our support for equality before the law and an independent judiciary are hugely important considerations in the House of Commons."
Mr Bercow's position caused a clash with Lord Speaker Lord Fowler, who vowed to keep an "open mind" about Mr Trump addressing Parliament.