London CNN  — 

The seemingly never-ending Brexit saga will enter a phase of unprecedented drama this week, as fears mount over a full-blown constitutional crisis and speculation grows about a possible general election.

The UK Parliament returns from its summer break on Tuesday, and it looks like all the players in this next act of deal or no deal are ready for a showdown.

Prime Minister Boris Johnson has vowed to take Britain out of the European Union by October 31, “do or die,” and shows no signs of deviating from his plan.

Johnson’s kamikaze approach has alarmed the more moderate voices in Parliament – including some lawmakers from his own Conservative party – who think a no-deal exit would be a disaster for the British economy and destroy the UK’s reputation among its allies. They are determined to prevent him from leading Britain out of the EU without a deal.

Last week, the Queen granted Johnson’s request for a five-week suspension of Parliament – ostensibly so that the government could reset the parliamentary timetable and launch a new legislative program. But the plan to prorogue Parliament was widely seen as an attempt to limit the time for Johnson’s opponents to prevent a no-deal. It’s been condemned as “undemocratic” and slapped with several legal challenges, including one from a former UK Prime Minister.

The race is now on to bind Johnson’s hands – this is how it could all shake out.

Parliamentary moves

When Parliament sits on Tuesday, it will be under the almost audible ticking of a stopwatch. Opposition lawmakers will have just a handful of days to pass legislation preventing a no-deal before next week, when Parliament shuts up shop until October 14.

When they return from the break, that ticking clock will only get louder. It’ll be a mere 17 days before Britain is due to leave Europe.

All of this sets up an epic clash between Johnson’s critics and supporters in Parliament.

The drama could play out in a number of ways. But first up, opposition lawmakers will need to wrest control of the day’s agenda, calling for an emergency debate – also known as a Standing Order 24 or SO24.

But it’ll be up to House of Commons Speaker John Bercow – a larger-than-life character in British politics – whether or not to grant an emergency debate. Given Bercow’s sympathetic view of the role that dissident voices play in Parliament, it seems likely he will allow it.

Boris Johnson delivers a speech at Downing Street on the eve of what is expected to be a tumultuous day in Parliament.

Assuming lawmakers succeed in calling that debate, they’ll need to quickly push through a bill blocking a no-deal on October 31. The text of that bill, which is expected to be backed by a group of opposition and rebel Conservative lawmakers, was published Monday night.

The law would force Johnson to seek an extension to the Brexit process until January 2020 if he failed to agree a new deal with the EU at a summit scheduled for mid-October, or to seek Parliament’s consent for for a no-deal Brexit. The latter scenario is unlikely given that a majority of MPs opposed a no-deal Brexit in previous votes.

If the rebels’ bill gets through the House of Commons, it would head to the House of Lords where “the possibility of filibustering – or time wasting – is greater,” said Professor Tony Travers, director of the Institute of Public Affairs at the London School of Economics.

Parliament doesn’t meet on Fridays, so Thursday would be the last sitting this week, though there is a possibility of an emergency sitting into the weekend.

Even if a law blocking no-deal did pass the House of Lords, senior government ministers – including Michael Gove and Gavin Williamson – have suggested the government could ignore it.

Indeed such a law could be challenged, “and the whole thing would head off to the courts,” said Travers.

Court actions

Outside Westminster, legal actions are underway in three courts across the UK to stop Johnson from suspending Parliament.

On Tuesday there will be court hearings for two of the cases – one including a group of over 70 pro-Remain politicians in Scotland, and the other in Belfast involving Northern Ireland campaigner Raymond McCord.

For McCord, the prospect of a no-deal Brexit is deeply personal. His son was killed during the Irish “Troubles” and he says a no-deal Brexit would violate the Good Friday agreement that ended more than three decades of violence in his homeland.

The Edinburgh hearing could also be explosive, with a lawyer for the MPs demanding a sworn statement from Johnson about why he is proroguing Parliament – meaning he could (in theory) be called to testify.

The third court hearing against Johnson’s suspension of Parliament is set for Thursday, this one launched by high-profile anti-Brexit campaigner Gina Miller, who successfully sued the government back in 2016.

Miller says that proroguing Parliament sets a horrifying precedent, and that Johnson’s government is “subverting democracy” in a way that is unprecedented.

John Major has joined Miller’s legal action, which means Britain will be treated to the extraordinary spectacle of the former Conservative prime minister suing the current Conservative prime minister.