WESTMINSTER reconvenes at 2.30pm tomorrow. There have been many crunch weeks in the course of the past few years, but this is the crunchiest so far. Why? Because last week’s prorogation crisis marked the rubicon where compromise is no longer possible between parliamentary Leavers and Remainers, or their sub factions.

It also marked the moment when the Brexit question turned into a full-blown British constitutional crisis on a scale that now threatens the viability of the whole political system. Here’s my guide to the horses and riders this week.

Will Labour move a vote of no confidence?

No. Labour has abandoned its plans to call for a vote of no confidence in Boris Johnson’s government. The reason for this is simple: not enough Tory rebels or LibDem MPs are willing to put Jeremy Corbyn into No 10 (even for a few weeks), while the Labour leadership won’t contemplate having anyone else.

Even if by some parliamentary miracle a successful vote of no confidence occurs this week, we would simply have a fortnight of utter political paralysis while the Remain parties squabbled over who might lead the interim administration. Put another way, the Tory Remainers and LibDems – when push comes to shove – prefer No Deal to a left-wing Labour administration. Who says class politics is dead?

What will Labour do?

Having dumped the idea of a no-confidence vote, Labour have revived plans to take control of the Commons Order Paper and attempt to pass a bill forcing the Government to seek an extension of Article 50. If successful,this would shift the October 31 deadline back in the hope of forcing Johnson to negotiate a softer deal. Parallel to this, there are reports that Brussels might offer the UK a unilateral extension on the timetable for Brexit, thus pausing the ticking Brexit clock from its side. Expect a vote tomorrow or Wednesday.

How vulnerable is the Government?

Despite his media honeymoon, Boris Johnson has a majority of just one in the House of Commons, and that assumes the 10 DUP MPs side with him in any division. However, what has changed since BoJo got into No 10 is the pressure being put on Tory MPs by Johnson’s personal political rottweiler, senior aide and fashion disaster zone Dominic Cummings.

Last week, the delightful Mr Cummings lost his rag (a frequent occurrence) with Chancellor Sajid Javid’s media advisor Sonia Khan. So he simply ordered members of the armed response unit on duty outside No 10 to escort Ms Khan off the premises forthwith.

Apart from being thuggery and intimidation of the worst kind, this is not the actual job of the diplomatic protection units, who are there to deal with potential terrorist attacks. If you can humiliate the Chancellor of the Exchequer with impunity, just think what lowly Tory backbenchers must be feeling.

The latest threat from Cummings is that any Conservative MP who dares vote with the opposition this week will be summarily deselected ahead of the imminent General Election. That won’t necessarily work as a number of hardline Remainers have already decided their career in the Tory party is effectively over, including former chancellor Philip Hammond.

According to the Daily Telegraph, 17 Tory MPs might revolt and back opposition attempts to impose legislation to block a hard Brexit.

My guess is this is exaggerated. However, with a majority of just one, any revolt would be problematic for Johnson.

Bottom line: can the Remainers win?

When push comes to shove, the odds on the Remainer side seizing control of the Order Paper this week are slim. Last April – the previous occasion when the opposition seized control of parliamentary business – the so-called Cooper-Letwin Bill passed by the narrowest of margins, 313-312.

Only 14 Tory MPs rebelled against Theresa May. I don’t think it will be very different this time around. But no fewer than nine Labour MPs voted to oppose Cooper-Letwin and support Mrs May. The prospect of keeping BoJo and Dominic Cummings in a job might cause some of these Labour rebels to repent but don’t hold your breath.

What happens if the opposition succeeds against the odds?

Even if these cunning manoeuvres take place, the Johnson government might simply ignore them. The Halloween Brexit deadline is already enshrined in UK law. It is a legal quibble whether passing a bill telling Johnson to seek an Article 50 extension from Brussels actually changes anything. Johnson could, for instance, simply forget to put a stamp on the letter to the European Commission asking for the extension!

On yesterday’s Andrew Marr programme, a poker-faced Michael Gove refused to commit the Government to implementing any opposition bill. Without doubt, for BoJo and co to prevaricate over implementing a bill extending Article 50 would detonate a nuclear constitutional crisis. But Boris is not Theresa. The real Brexiteers are now in charge. Don’t expect them to knuckle under easily – as the prorogation move demonstrated.

Will there be a General Election?

Very probably. Johnson’s commitment to massive public spending increases is proof positive that he is preparing the ground for an election run.

His strategy is to secure Brexit first, in order to see off Nigel Farage. BoJo’s default position, if Brexit has not occurred by voting time, is to make sure he pins the blame for any delay on Brussels, Corbyn and the Tory Remainers. Boris wants to run on an anti-elites platform – outrageous given he’s an Eton-educated Tory toff. But then, Boris is a chancer.

A General Election could be triggered this week. If the Article 50 extension bill fails to get on the Order Paper, that leaves Jeremy Corbyn with the option of putting down a no-confidence motion on Thursday, which must be debated. Corbyn may bottle this or delay it till Parliament returns after its extended prorogation. In either case, he loses the initiative and looks like a ditherer.

Alternatively, Boris may call everyone’s bluff and put down a motion calling for an election himself. He will probably do this anyway if an Article 50 extension is imposed on the Government. That’s the simple way of avoiding implementing such legislation. Also, calling an election for October means campaigning will still be possible before the winter dark nights set in. This is a consideration for the Tories, as their voting base is quite elderly.

Recent polls look good for Johnson and the Tories at a UK level. Although they are 10 points down on 2017, Labour have lost even more, sinking to 25%. The Brexit Party is well down on its EU election score.

On current form, Johnson could make net gains of 10 or a dozen seats while Labour would lose as many as 40. Of course, Corbyn has shown an ability to campaign strongly and public opinion may polarise in an election around things other than Brexit.

The SNP will gain heavily, opening the possibility of a progressive alliance. However, the ultimate conclusion is that whoever wins the General Election, the implosion of the British political system will continue apace. This week may be a crunch week but there are many more to come.

Anyone for indyref2?