Boris Johnson has warned that if the British government loses this evening's key Brexit vote, it will pull the whole bill and push for a general election.
MPs will have their say this evening on whether to support the three-day timetable to get the deal through the House of Commons.
Mr Johnson is eager to have the bill passed as soon as possible so the UK can leave the EU next week, without the need for any extension.
However, the bill itself runs to 110 pages with another 124 pages of explanatory notes - prompting concern from MPs that they will not have time to scrutinise it fully due to the rushed debate timetable.
Speaking in the House of Commons, British Prime Minister Boris Johnson urged all sides to back his agreement.
He said: "I will in no way allow months more of this.
"If parliament refuses to allow Brexit to happen, and instead gets its way and decides to delay everything until January or possibly longer, in no circumstances can the government continue with this.
"And with great regret, I must say that the bill will have to be pulled and we will have to go forward to a general election."
"Utterly ludicrous"
Labour leader Jeremy Corbyn has vowed his party will oppose the tight timetable.
He argued: "We got the bill at 8:15pm last night - and this afternoon at one o'clock we start debating. It's ludicrous... utterly ludicrous.
"These are serious issues that have huge implications for communities, factories, jobs and people."
Today's votes are due to take place at around 7pm.
One is a motion to move the bill to a second reading - a key and routine step in moving the bill to the next stage in parliament.
However, the crucial vote will be on the 'programme motion' - the timetable being proposed by the government.
Mr Johnson has already requested a Brexit extension from the EU, but European officials have indicated they're waiting to see how events play out in Westminster before making a decision.
Speaking earlier today, European Council President Donald Tusk said: “It is obvious that the result of these consultations will very much depend on what the British parliament decides or doesn't decide."
