The House of Commons speaker is under increasing pressure after a debate on a ceasefire in Gaza descended into chaos.
Sir Lindsay Hoyle sparked fury from SNP and Conservative MPs when he broke with convention to allow a vote on a Labour motion for an “immediate humanitarian ceasefire”.
Sir Lindsay later apologised, but still faces calls to resign.
Some 33 Tory and SNP MPs have signed a motion declaring they have no confidence in the Speaker.
Apologising in the Commons after the vote, Sir Lindsay told MPs he takes responsibility for his actions, and that he will meet key figures from the main parties to discuss what happened – although it is unclear when this will take place.
The row erupted in the Commons on Wednesday, on a day which had been designated an SNP opposition day, meaning the Scottish nationalists could put forward motions for debate and vote.
The SNP had originally tabled a motion calling for an “immediate ceasefire” in Gaza. Normally this would have meant MPs would debate and vote on this motion, before moving on to any amendments tabled by other parties.
However, Sir Lindsay broke with tradition and allowed a Labour amendment on the SNP motion first, prompting fury from both the SNP and the Conservatives.
The Speaker later said he had come to this decision so that MPs could express their view on “the widest range of propositions”.
Labour’s amendment, which called for an “immediate humanitarian ceasefire” noted that Israel “cannot be expected to cease fighting if Hamas continues with violence” and called for a diplomatic process to deliver “a safe and secure Israel alongside a viable Palestinian state”.
While the initial motion tabled by the SNP went further, calling for an “immediate ceasefire” and an end to the “collective punishment of the Palestinian people”.
The government’s proposal did not go as far as that put forward by Labour, and called for “an immediate humanitarian pause”.
In allowing a vote on the Labour motion first, Sir Lindsay was met with accusations he had allowed the vote to be “hijacked” by Labour.
Sir Lindsay’s decision meant Labour leader Sir Keir Starmer avoided another potential rebellion over the party’s position on Gaza as Labour MPs were able to show their support for a ceasefire without voting for an SNP motion.
Last November Sir Keir suffered a major revolt when 56 of his MPs, including 10 frontbenchers, defied him to back an SNP motion urging an immediate ceasefire.
Labour’s amendment went through to loud shouts of “aye” without a formal vote, after the government said it would not take part in protest.
This meant there was no vote on the SNP’s motion which was originally meant to be the focus of the debate.
The government does not have to adopt Labour’s position as the vote is not binding.
SNP MPs and some Tories were seen walking out of the chamber over the Speaker’s handling of the vote.
Commons leader Penny Mordaunt said Sir Lindsay had “undermined the confidence” of the House and suggested his decision had allowed the debate to be “hijacked” by Labour.
She said this had “raised temperatures in this House on an issue where feelings are already running high”.
Sir Lindsay later returned to explain his decision and apologise.
Amid shouts of “resign”, he said: “I thought I was doing the right thing and the best thing, and I regret it, and I apologise for how it’s ended up.
“I do take responsibility for my actions, and that’s why I want to meet with the key players who have been involved.”
SNP Westminster leader Stephen Flynn said whilst he acknowledged the Speaker’s apology, Commons officials had warned the decision could lead to his party not having a vote, on a day which had been designated an SNP opposition day.
Visibly furious, he said his party had been treated “with complete and utter contempt”.
“I will take significant convincing that your position is not now intolerable,” he added.
In a statement after the debate, Mr Flynn claimed it was “a disgrace that Sir Keir Starmer and the Speaker colluded to block Parliament voting on the SNP motion”.
“This should have been the chance for the UK Parliament to do the right thing and vote for an immediate ceasefire in Gaza and Israel – instead it turned into a Westminster circus,” he added.
He later told the PA news agency: “I think we probably need a wee bit of an investigation into what has happened here.”
A source close to the Speaker said the suggestion he was pressurised by the Labour Party was “absolutely untrue”.
The source said that Sir Lindsay did not take the decision lightly, and added that he was conscious that MPs, their families and staff were dealing with a lot of pressure and was mindful of their safety.
In response to the claims of “collusion”, Sir Keir accused the Conservatives and SNP of “choosing political games over serious solutions”.
Speaking to BBC News, Shadow Defence Secretary John Healy branded the allegations of collusion “rubbish”.
“The Speaker was rightly playing his role, he’s there to protect the rights of all MPs, he was wanting to ensure the widest possible debate, and he wanted to make sure that the main plans or propositions from Labour, the Conservatives and the SNP, the three main parties all had a chance to be put to the vote.”
Several MPs have called on the Speaker to step down, and 33 Tory and SNP MPs have declared they have no confidence in him by signing an early day motion.
While very few early day motions are debated, they allow MPs to show their support for an issue – in this case unhappiness with Sir Lindsay’s actions.
SNP MP Pete Wishart was one of the MPs to put their names to the motion, and said he had done so because the “position of the Speaker is pretty much untenable”.
However, many other MPs said they would not be taking this step.
Former Conservative minister Robert Buckland said he accepted the Speaker’s apology and would not be asking for a vote of confidence.
The chaotic scenes in the Commons overshadowed the debate on whether there should be a ceasefire in Gaza, even as thousands of pro-Palestinian demonstrators gathered in Parliament Square.
Conservative MP Tobias Ellwood said he was “dismayed” by the scenes in Parliament, saying that the debate was meant to be “a real opportunity to underline where we believe the conflict should go and how we resolve this and I’m afraid there was politics being played on both sides”.
Sir Lindsay was first elected as a Labour MP but after becoming Speaker he relinquished his party affiliation, as is the convention.
Earlier this week, Labour shifted its position to call for “an immediate humanitarian ceasefire”, following months of pressure from backbenchers and activists.
Israel launched its operations in Gaza following an attack by Hamas on southern Israel on 7 October, during which about 1,200 people were killed and more than 240 others taken hostage.
Since then, Israel’s military campaign has killed more than 29,000 people in Gaza, according to the Palestinian territory’s Hamas-run health ministry, whose figures are accepted by the United Nations.