All eyes will be on Commons Speaker John Bercow on Monday afternoon as Boris Johnson pushes for a knife-edge Commons vote on his Brexit deal.
The Prime Minister was forced to abandon such plans during a special Saturday sitting of the Commons after suffering an embarrassing defeat at the hands of former Tory minister Sir Oliver Letwin, which resulted in him having to ask the EU for a Brexit extension.
Commons Leader Jacob Rees-Mogg told MPs the Government aimed to hold a meaningful vote on the Brexit deal on Monday - though Downing Street says the vote will be pulled if amendments are selected that would render the vote "pointless".
However, in order for a vote to be held, Mr Bercow - who Tory Brexiteers have accused of being pro-Remain - will rule on whether the Government can bring a so-called “meaningful vote” on its plans.
However, the Speaker could rule that such a vote effectively happened on Saturday and cannot be repeated so soon.
Should the vote be blocked, focus will switch to the Government bringing its Withdrawal Agreement Bill (WAB) - the legislation required to implement the Brexit deal - before MPs on Monday, with a vote on its second reading on Tuesday.
The Government will pull the vote on its Brexit plans if any amendments are selected that would "render the vote pointless", Downing Street has said.
The Prime Minister's official spokesman told a Westminster briefing: "The meaningful vote will go ahead if the Speaker allows it and if no amendments are selected which would render the vote pointless.
"There is no point having a meaningless vote - the Government would pull the motion.
"We will go ahead with the introduction of the WAB (Withdrawal Agreement Bill) with second reading tomorrow.
"The public want Brexit done - the Government is determined to pass the PM's great new deal and get us out of the EU on October 31."
Ministers insist they “have the numbers” to push the agreement through, but the parliamentary situation appears to be on a tightrope.
Justine Greening MP told ITV News that even if the deal were to pass, Brexit would not be over and the effects would be felt for decades.
She therefore believes Parliament needs time to properly scrutinise the bill.
Labour has made clear it will try to hijack the legislation by putting down amendments for a second Brexit referendum and a customs union with the EU.
Shadow Brexit secretary Sir Keir Starmer indicated Labour could even back the WAB if it was put to voters in a national poll against a Remain option.
On Sunday, he laid out Labour's plan for the week ahead to ITV News, saying step one is to "make sure that that extension is granted if we possibly can".
Number 10 restated its opposition to Labour's plans.
"The Government is opposed to both a customs union and a second referendum," the PM's spokesman said.
"Both of those have been voted on on a number of occasions in the House of Commons and neither have been successful."
Shadow solicitor general Nick Thomas-Symonds said that Labour MPs will call for a confirmatory referendum, adding that he thought Parliament may vote in favour of Britain staying in a customs union with the bloc.
“A customs union is going to be one of the amendments that comes through and that is something that is going to have a very good chance of getting a majority,” Mr Thomas-Symonds told BBC Radio 4’s The Westminster Hour.
The DUP was reported to be considering backing Labour’s move to force a new customs union with the EU into WAB legislation.
However, party chief whip Sir Jeffrey Donaldson told BBC Radio 5 Live he wanted to engage with the Government to see “where things stand”.
But, in a column for The Daily Telegraph, International Trade Secretary Liz Truss said making a customs union part of any pact “would take us back to square one and render the UK unable to strike our own bilateral trade agreements around the world”.
Despite being forced by Parliament to request a Brexit delay from Brussels after another embarrassing Commons defeat on Saturday, Mr Johnson and Ministers are talking up their chances of rushing Brexit legislation through.
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The move came amid reports that the EU was considering offering the UK a “flexible extension” to February, allowing it to leave whenever an agreement is secured.
The PM is striking a bullish stance as he faces another rollercoaster week in the Commons, insisting the UK will still quit the EU in 10 days.
He abandoned plans for a meaningful vote on a Saturday sitting of the Commons after suffering an embarrassing defeat at the hands of former Tory minister Sir Oliver Letwin.
But the PM had not suffered a loss but achieved a “boost to his strategy”, according to former Tory leader Iain Duncan Smith.
“For every time he is forced to take a defiant stand against the Remainers in Parliament, it only becomes clearer to the British public just who is fighting desperately and against the odds to deliver their wishes, and who is to blame for the fact that Brexit is not yet over,” Mr Duncan Smith wrote in The Daily Telegraph.
After losing the vote, Mr Johnson had no option but to write to European Council President Donald Tusk, as Parliament demanded, requesting a three-month extension to the end of January.
The PM did not sign the letter, and sent a second communication insisting that a delay would be “deeply corrosive” for the UK and the EU.
Mr Johnson had been legally required to send the letter as he had not gained the backing of MPs for his plan, but in it he stressed to Brussels he was only sending the document at Parliament’s bidding.
Shadow chancellor John McDonnell accused Mr Johnson of “behaving a bit like a spoilt brat” in the way he communicated with Brussels over the extension request.
He said the PM could be in contempt of Parliament and the courts over the issue.
If the PM’s deal is amended he will have no choice but to accept a long delay to the UK’s departure from the bloc.
A Government source said: “Parliament needs a straight up-and-down vote on the deal… or do they want to frustrate and cancel Brexit altogether?
“We cannot allow Parliament’s letter to lead to Parliament’s delay.”
The source said the WAB would need more late-night and weekend sittings by MPs.
Asked on Sunday if the EU was going to be open to an extension, its chief negotiator, Michel Barnier, said Mr Tusk would consider the next stage.
It is likely that the EU will assess the situation in the Commons before formally responding to the extension request.