Parliament debate on Tuesday is MPs’ first opportunity to vote on the principle of the PM’s EU withdrawal bill.

UK Prime Minister Boris Johnson is a tenacious fellow. Despite mounting failures highlighting his inability to govern the country through the House of Commons, he is sticking at it in a bid to save face and push through a Brexit deal in the coming nine days – or else break his “do or die” pledge to leave on October 31.

Johnson said he would “rather be dead in a ditch” than request a delay from the European Union, yet he was eventually forced to request just such a delay. The EU is taking the request seriously, with European Council President Donald Tusk on Tuesday reassuring MPs a delay is still on the table as he consults with European leaders.

“It is obvious that the result of these consultations will very much depend on what the British Parliament decides, or doesn’t decide,” he said.

With that in mind, we turn to the British Parliament.

On Monday, Johnson was forced to abandon his attempt to have a second straight “yes or no” vote on his Brexit deal, having lost the first vote on Saturday. Instead, he is trying to speed through the entire legislation for Britain to leave the EU through the lower and upper houses of parliament in a matter of three days.

After more than three years of negotiations, it is unclear as to how, whether or when a deeply divided Britain will leave the bloc, more than 40 years after the country joined the project.

The withdrawal agreement bill, published late on Monday ahead of Tuesday’s debate, is a 110-page piece of legislation, accompanied by another 400 pages of legal text, which implements the terms of the Brexit deal in British law. It has to pass through several stages in each of the parliament’s two chambers before it becomes law.

Tuesday: The second reading

Despite being called “the second reading”, this is MPs’ first opportunity to debate the principles of the bill.

It is followed by a vote, which the government must win to proceed to the next stage of legislation. This vote is expected at 18:00 GMT.

The government believes it has a wafer-thin majority, maybe as thin as four or five MPs, to pass this stage – even though the principal opposition Labour Party and other rival parties are expected to oppose it.

If it does pass, it will mark only the second time Johnson has won a parliamentary vote since taking office at the end of July.

The programme motion

The government then has to lay out the timetable for the remaining stages of the legislation and have MPs approve the timetable.

This is the vote to watch most closely. It is expected shortly after 18:00 GMT.

Johnson wants to push through the legislation in time for Britain to leave on October 31, but some who support the deal in principle are uncomfortable with passing such an important piece of legislation so quickly.

David Allen Green is a former government lawyer. He said it would take him two weeks to have a sense of all the implications of the legislation and questioned why a draft had not been published long ago for scrutiny.

“It has been irresponsible of government not to publish this bill before now, in draft for consultation,” he posted on Twitter. “It is yet more irresponsible for the government to try and to push it through the Commons in three days. And it will be most irresponsible of all for MPs to let them do this.”

When a previous deadline was looming, Nikki da Costa – who became Johnson’s director of legislative affairs – said Brexit legislation would require “more than four weeks” of scrutiny.

Only a handful of those in favour of the deal would have to object to its timetable for Johnson to lose the slim majority he believes he has behind him.

If Johnson loses on the timetabling – his eighth loss of the 10 parliamentary votes he has faced – his plans for the UK to leave the EU on October 31 will likely be scuppered.

The committee stage

Once a timetable for the debate is agreed, it will begin in earnest. At this stage, MPs propose changes to the bill.

There is a chance it may not get to this – if Johnson loses the programme motion, his administration may admit defeat, knowing there would be no way to “get Brexit done” by October 31, and withdraw the legislation. If that happens, he will likely call strongly for a snap election to change the parliamentary arithmetic, and a Brexit delay until at least the end of January. It would be a humiliating climbdown for the prime minister.

But if the committee stage goes ahead, MPs will be testing support for a second Brexit referendum, or to commit the government to seeking a customs union with the EU in its long-term future relationship.

Neither of those could be supported politically by the government, and if either were to win majority support in the Commons and become attached to the legislation, the whole deal would likely be withdrawn by Johnson’s administration.

The government has indicated that negotiations with the EU are closed, so any amendment approved by Parliament and changes to the shape of the deal would be highly problematic.

The government has proposed three hours of debate at this stage on Tuesday, following the programme motion vote.

Wednesday: More committee stage debate

There are 12 hours scheduled for further discussion on potential amendments on Wednesday, starting after 12:00 GMT.

Discussions on second referendum amendments are more likely on Wednesday.

Thursday: Report stage and ‘third reading’

If the bill makes it this far in some manner somewhere close to the original plan Johnson proposed, parliament will have another chance to debate it and make changes, before it is put to a final vote and handed off to the House of Lords.

The government has proposed eight hours of debate for Thursday, which is likely to begin after 09:30 GMT.

Friday: Peer pressure

The House of Lords, the UK Parliament’s upper chamber, will begin scrutinising and amending the bill through several stages and rounds of voting.

There are no programme motions in the Lords, so no strict timetabling. They will debate the legislation for as long as they feel the need, and peers have been known to take sleeping bags and toothbrushes into their offices when lengthy proceedings are looming.

It will likely take several days to get through the Lords – and any changes would then have to be approved by the House of Commons before the law can be finalised.

EU response

The European Parliament can only clear the new exit agreement reached with London once the UK Parliament has ratified it, European Commission President Jean-Claude Juncker said.

“We need now to watch events in Westminster very closely, but it’s not possible, not imaginable, that this parliament would ratify the agreement before Westminster has ratified the agreement. First London, then Brussels and Strasbourg,” Juncker told politicians in the European Parliament in Strasbourg.

Tusk said the EU should be “ready for every scenario”.

“But one thing must be clear: as I said to Prime Minister Johnson on Saturday, a no-deal Brexit will never be our decision.”

General election?

Both the governing Conservatives and main opposition Labour Party, led by Jeremy Corbyn, say they want a new election, but Corbyn has said he will not back any move to hold one until a no-deal Brexit is ruled out.

Other senior opposition figures want to take advantage of Johnson’s numerical weakness in Parliament to force through a second Brexit referendum before heading to the polls.

“An election is inevitable because of the numbers in Parliament, because we have got to break the impasse, the timing will be a matter for Jeremy Corbyn,” Labour’s Brexit spokesman Keir Starmer said on Sunday.

“But it is inevitable that sooner or later this breaks into a general election.”