Events in Northern Ireland are so volatile at present that it is probably futile to try and predict with any certainty what the state of play will be in 2024. But as the row over the Protocol drags on, that date looms large in the thoughts of some in Whitehall.

Why? Because the first vote under the ‘consent mechanism’, which gives the Province the opportunity to give democratic consent to the operation of parts of the Protocol (specifically articles 5-10) is due to be held in December of that year.

But what happens if, as is at least plausible if not likely, Stormont has collapsed by then and isn’t sitting when the date arrives? Nobody knows. There is no provision in the agreement for such a scenario. It apparently keeps some on the UK side up at night.

There are two possible reasons why the accident-prone Northern Ireland Assembly might have fallen over (again) in the next couple of years.

First, Sir Jeffrey Donaldson might follow through on his threats to take the Democratic Unionists out of the power-sharing Executive if the Government doesn’t secure the changes Unionists want to the Protocol.

This isn’t something the DUP seem keen on doing. Their MLAs and staffers like their jobs, and apart from a brief period at the very beginning the party has not historically been well-disposed towards Westminster rule. Just this week, Donaldson allowed his original deadline to pass by, saying it would be “churlish” to pass by when Lord Frost seemed to be making progress.

Loyalists marked the occasion by hijacking and burning a bus. Both the DUP leadership and, crucially, their Conservative counterparts in London are aware that they cannot afford to let the EU drag the process out into December, let alone the New Year. One or the other will likely act before the end of the month.

Assuming the DUP don’t walk out now, there remains the second possibility: that they refuse to form an Executive after next year’s Assembly elections because Sinn Fein emerge as the largest party.

Under the terms of the St Andrews Agreement, under which a complaisant New Labour allowed the two big Ulster parties to stitch up Stormont, it is now the largest party, and not as previously the largest bloc, that gets to nominate the First Minister. Whilst they and the Deputy First Minister are in truth a co-equal executive, the optics matter to Unionists (which is why they insisted on the fiction in the first place).

Both these scenarios would put Brandon Lewis in a difficult position. Traditionally, previous Secretaries of State have overseen a few rounds of interminable summitry before bribing the parties back into Stormont. But that was when the difficulties were caused by issues that were ultimately in Westminster’s sole gift, which the terms of the Protocol are not. Likewise, reform of the Assembly’s procedures may be necessary and overdue but would be extremely difficult to deliver if the object seemed to be simply denying Sinn Fein the First Minister’s office.

If the Unionists fail to regain their old majority in the Assembly, one can also imagine that it might suit the DUP et al to jam the institutions rather than see the nationalist parties and the Alliance give the Protocol their stamp of approval.

That leaves open one especially intriguing possibility. What if a splintered Unionist vote sees Sinn Fein returned as the largest party, but an energised and mobilised Unionist electorate sees the combined pro-UK parties regain the majority they held until only a few years ago?

When negotiating the ‘consent mechanism’, Brussels insisted that the Belfast Agreement’s usual provisions about cross-community support were set aside. A bare majority in Stormont is all that’s required. So long as unionists don’t have a majority, this looks like smart tactics (although it puts another question mark over their claimed status as guardians of the Good Friday Agreement). If they regain it, however, they will be able to vote down large parts of the Protocol despite nationalist opposition.

Might this prospect be enough to persuade the Unionist parties to swallow a republican First Minister, at least for a couple of years? Would Sinn Fein even want to form an Executive with the prospect of a Unionist veto on the consent mechanism in the offing?

What an exciting few years await the Northern Irish Secretary.