In dramatic scenes, Lloyd Russell-Moyle swung the antique symbol of parliamentary authority from its holder after the government confirmed it would delay the vote on the prime minister's Brexit deal.
Tory MPs screamed "expel him" as Mr Russell-Moyle was promptly asked to leave the chamber by Speaker John Bercow.
The incident came after Ms May faced fury from MPs for calling off a vote on her Brexit deal, in an attempt to seek further "assurances" from the EU.
The prime minister admitted her blueprint would have been "rejected by a significant margin" on Tuesday due to major rebellion by Conservative MPs, as she confirmed plans in an eleventh-hour Commons statement.
Labour leader Jeremy Corbyn secured an emergency debate on the delay on Tuesday, saying "the government’s incompetence can’t be used as an excuse to threaten the country with no-deal".
It comes as the European Court of Justice (ECJ) ruled that the UK can unilaterally revoke Article 50 and stop the Brexit process following a "democratic process".
See below to read our coverage of events as they happened
Brexit: Conservative leadership rivals circle Theresa May ahead of expected defeat in crunch Commons voteTheresa May is set for the bleakest week of her time in power after leadership rivals publicly positioned themselves to grab the Tory crown if her Brexit plans collapse.Ex-cabinet ministers Boris Johnson, Dominic Raab and Esther McVey all signalled a willingness to bid for the leadership amid speculation that Ms May faces a heavy defeat in the crunch Commons vote on her proposed Brexit deal.
Environment secretary Michael Gove has said a vote on the PM's Brexit deal will go ahead on Tuesday. Asked on BBC Radio 4's Today programme whether it was a "100%" happening, he replied: "Yes".
"The vote is going ahead," he said.
Mr Gove also said: "Of course we can improve this deal, and the prime minister is seeking to improve this deal, but the backstop has been depicted by some as a vice for the United Kingdom - and clearly there are uncomfortable aspects to it.
"But, for the European Union, they have done what they said they would never do in these negotiations - they have split the four freedoms, they have allowed us to cherry-pick, and it will be the case for EU politicians, incredibly uncomfortable, and have to explain to their electorates that they are allowing unimpeded access for British goods into their markets, while Britain is not paying for that access and Britain has control of its borders."
Mr Gove added it was "extremely unlikely" that he would stand as a future Conservative Party leader.
And he said Ms May "absolutely" could win the vote on Tuesday, adding: "I hope that everyone who has a vote will reflect on how momentous that decision is and will vote to honour the decision of the British people to leave the European Union and in a way that ensures that we leave in a smooth, orderly and democratic manner."
UK can stop Brexit by revoking Article 50, Europe's top court rulesThe UK has the legal power to stop Brexit by unilaterally revoking Article 50, the EU's top court has ruled.The ruling matches legal advice given to the court last week by its advocate general, who said as a sovereign country Britain could reverse its decision even at this late stage. The legal decision is significant because means Britain could prevent a no-deal Brexit from happening if it wanted, even if Theresa May's deal is voted down by MPs next week.In their judgment released on Monday morning the panel of judges said it would be “inconsistent with the EU treaties’ purpose of creating an ever closer union among the peoples of Europe to force the withdrawal of a member state” against its wishes.
Scottish first minister and SNP leader Nicola Sturgeon has said the ruling this morning from the ECJ on Article 50 is an "important judgement".
"So an extension of Article 50 to allow time for another vote, followed by revocation of Article 50 if the outcome is Remain seems to be an option that is now open to the House of Commons."
The case was brought forward in February by a group of Scottish politicians - Labour MEPs Ms Stihler and David Martin, the SNP's Joanna Cherry MP and Alyn Smith MEP, Green MSPs Andy Wightman and Ross Greer, and lawyer Jolyon Maugham QC, director of the Good Law Project.
The European Court of Justice (ECJ) found that if the UK does decide to revoke Article 50 and stop the Brexit process, it would remain in the EU as a member state and the revocation must be decided following "democratic process".
Responding to the ruling, the constitutional relations secretary Michael Russell MSP added: "This is a hugely important decision that provides clarity at an essential point in the UK's decision-making over its future relationship with the EU.
"People in Scotland overwhelmingly voted to remain in the EU and that continues to be the best option for Scotland and the UK as a whole.
"This judgment exposes as false the idea that the only choice is between a bad deal negotiated by the UK Government or the disaster of no deal.
"We now know, thanks to the efforts of Scotland's parliamentarians, that remaining in the EU is still on the table."
Molly Scott-Cato - the Green MEP, who is also the party's Brexit spokesperson - has responded to the European Court ruling, saying:
"The ECJ ruling has lit up the path out of the Brexit calamity. MPs should vote down the withdrawal agreement tomorrow and then support a People's Vote. If the country support continuing EU membership the court has told us we can revoke Art 50 and keep our existing terms. The threat to this strategy comes from Labour whose posturing around mythical renegotiation and a general election would waste the time we need to organise the referendum."
This is from the Daily Mail's political editor Jason Groves. He claims Theresa May is about to hold a conference call with cabinet ministers on the eve of the crucial Brexit vote.
The Commons committee on standards has just published its response to Dame Laura Cox's report into bullying and harassment of parliament's staff, writes my colleague Ashley Cowburn.
It says greater freedoms should be given greater freedom to trigger investigations into historical investigations against MPs.
The publication examined initial proposals for the House of Commons' standards system following Dame Laura Cox's report, which lifted the lid on a toxic culture at Westminster.
The committee report said: "We agree with the commissioner's view that the requirement for her to consult the committee before beginning an inquiry relating to events more than seven years earlier is an unacceptable encroachment on her independence.
"We therefore recommend that this requirement should be abolished and that future editions of the guide to the rules should reflect this.
"We believe there should be no exceptions to the general principle that the committee does not seek to direct the commissioner's operational decision-making.
"For that reason, we also recommend that the requirement for her to consult the committee before beginning an inquiry into a former member should also be abolished and that future editions of the guide to the rules should reflect this also.
Labour MP Kate Green, who chairs the committee, said: "It is vital that trust in the process is rebuilt, following the criticisms in Dame Laura Cox's report.
"Whilst there is clearly much more to be done, our recommendations will make an important step forward towards a fairer, more independent and credible system.
"The Standards Committee is unique in having an equal number of MPs and lay members on it, and these proposals will ensure that the skills and expertise of the lay members can help to hold MPs to account in the most effective way."
No 10 has confirmed that there will be a Cabinet conference call at 11.30am but insisted this is to update ministers on Theresa May's conversations with EU leaders over the weekend, rather than about any plans to call off tomorrow's vote.
A spokesperson said the vote will go ahead as planned and Ms May is "confident" of winning it.
Register for free to continue reading
Registration is a free and easy way to support our truly independent journalism
By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists
Already have an account? sign in
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies