At the Freudenstadt Symposium on European Regionalism this past weekend I was rather flummoxed by a nevertheless amusing question by someone in the audience. Are there any implausible, but still just about viable, Brexit scenarios you have not thought about? I was asked after I had presented my latest Brexit Diagram.

So here, rather tongue in cheek, and with the assistance of my Twitter followers, are 10 such scenarios!

1. May decides to revoke Article 50

The Miller case indicated that Parliament had to grant the Prime Minister the power to invoke Article 50 to start the procedure for the UK’s exit from the EU. But as Ewan McGaughey argues here, now the Prime Minister has that power, she could use it to revoke Article 50 as well. So, before going to Buckingham Palace to tender her resignation to the Queen, Theresa May could pen a letter to Donald Tusk saying she wants to give her successor a clean slate and the way to negotiate Brexit as he sees fit – so Article 50 should be revoked to stop the Brexit clock ticking.

2. Hunt wins the Tory Leadership, and aims for Soft Brexit

Somehow all the polling gets it wrong and Jeremy Hunt wins the Tory Leadership. And then Jeremy Hunt actually returns to being what plenty of people thought he was – a Soft Brexiter, and aims for that, and seeks to get a Deal through Parliament with Labour support. Maybe that destroys the Tory Party (as YouGov found)? Or maybe that poll was wrong too? (thanks @mwarne and @BirgitC for this one!)

3. Boris Johnson decides the best way to stay in power is to announce a Brexit referendum

Boris Johnson reputedly wrote two Telegraph columns before coming out in favour of Brexit – the other one favoured Remain. No-one has ever been really sure about his commitment to Brexit. But his commitment to his own advancement… that is not in doubt. A General Election might make Johnson’s Premiership the shortest ever, so what better way to solve the issue than – reluctantly – announce there ought to be a People’s Vote?

This he could justify by saying he has new information upon becoming PM about how bad the predicament would be if No Deal Brexit came to pass. If a referendum went for Leave, Johnson has a mandate for Brexit and can stay as Prime Minister. If it goes for Remain, he reluctantly accepts the result and the Tory Party are in no place to fight a General Election, so Johnson survives as PM until 2022. In his dreams. (thanks @_lisacostello for this one)

4. Boris Johnson decides to tone down the rhetoric, and advocates Brexit Delay to find a deal

This one is a variation on number 3 above, in that it assumes that Johnson wants to cling to power – which is not a foolish assumption. But instead of going for the radical option, Johnson fudges – he says he realises the complexity of the predicament, and understand the annoyance of the EU, and that the UK needs more time to work out what to do. No, I can’t see him doing that either, but theoretically a Prime Minister with some brains could try it.

5. The Darroch fiasco, or some other major scandal prevents Boris Johnson becoming PM, even though he wins the Tory leadership ballot

The source of the leak of the Darroch cables about Trump is still being determined… but what if Johnson himself had been the source of the leak? Actually too plausible some of my Twitter followers said. But surely the critique of Johnson would reach fever pitch were that to actually be the case. But could some other scandal down him? A resumption of tensions with Carrie Symonds? Or some skeleton from his past? I suspect nothing like this could end Johnson’s effort to become Prime Minister though – he would bluster it was all some sort of Remain conspiracy anyway, and probably survive.

6. The Queen puts the criterion on Boris Johnson becoming PM that he has to submit himself to a confidence motion

This one would be a bit of a constitutional innovation, but conversely we do not actually know how the Queen should deal with the current fragile majority for the Conservatives + DUP (see this excellent piece from the UCL Constitution Unit). Could the Queen say OK, Johnson, I want you to be Prime Minister but under the condition that you submit yourself to a vote of confidence in the Commons? (thanks @pwb and additional arguments from @tonykilner for this one)

7. The Queen appoints a caretaker Prime Minister as successor to Theresa May

If – as everyone suspects – Johnson wins the Tory Leadership election, what happens if he cannot command a majority of MPs? Or, to put it more concretely, that some MPs cross the floor to deny him a majority? The assumption would be that the Queen would ask May to continue a little longer, and for the recess in the Commons to be postponed. But there might be another way – appoint a sort of caretaker Prime Minister. Although there is no formal definition of this in law, such a PM (Lidington? Benn?) could command a majority in the House temporarily so as to consult as to what to do – to hold a General Election, to hold a referendum, and to perhaps ask the EU for more time – due to the UK’s political instability. Such a person would be rather untainted by May’s divisive premiership and could genuinely reach out to the other side of the Commons. It would actually be a rather sensible way forward, so that renders it unlikely.

8. Sinn Féin take their seats in the House of Commons

A guaranteed way to deny the Tories their majority, and to stop a Hard Brexit and hence avoid a hard border in Ireland… would be for Sinn Féin to take their seats. Sadly Mary Lou McDonald has rejected the idea. “We have no business in Westminster” she has said, but you could argue that – for their voters – they ought to have business to block Brexit, or at least lessen its impact. Sit once, down Johnson, then go again? (thanks @somersetchris for reminding me of this)

9. The Metropolitan Police arrest Aaron Banks or other Leave campaign staff

This one has been rumbling around for some time now – 3 MPs are even seeking judicial review to find out why the Metropolitan Police has not made any progress in the case and no arrests have been made. Could some arrests, and criminal wrongdoing by the Leave campaign, finally break the idea that the referendum was unlawful and ought to be re-run? That the Met will act speedily, or that anything could end pro-Brexit people trotting out the line that Leave was the “will of the people”, are both highly implausible. A variant of this is a development of point 3. above – that Johnson says he as information about misconduct of Leave campaigners that he was not aware of before becoming PM and uses this as an argument to either postpone Brexit or make the case for a 2nd Referendum. (thanks @lawpleb for this one)

10. An escalation of tensions with Iran distracts everyone from Brexit

“What about a war?” – with the Falklands in mind – is a well known political distraction tactic. Tensions are growing in the Arabian Gulf, specifically towards Iran. And Johnson already has form inflaming the situation in Iran (Zaghari-Ratcliffe). Could something like an attack on a UK registered tanker in the Strait of Hormuz distract everyone from Brexit?

[UPDATES]

These were ones missed off when I first posed the blog post…

11. Prorogue Parliament

This blog post was meant to be somewhat tongue in cheek, but there is the improbable and destroy-democracy route – to prorogue Parliament. This is probably legally possible (more details about it here), but politically I cannot see Johnson doing this one. (Thanks @MarkyGoodrich for reminding me)

12. Revert to a Northern Ireland only backstop

The original form of the Backstop was intended to apply to Northern Ireland alone. One of the criticisms of it by Tories has been that in the updated version is saddles the whole of the UK with a Customs Union with the EU into the medium term. Johnson could aim to ditch this, meaning customs checks would then be on the ferries in the Irish Sea. The DUP would withdraw their support from him, but he would then be free to seek to deliver the Hard Brexit he wants, and even some Labour MPs might back him on this. It would most likely need a General Election to solve the issue though. (Thanks @seandanaher5 for this one)

13. The Queen dies or abdicates

Would you want to have to meet Boris Johnson once a week? When you are 93? No, me neither. If the prospect of that were not enough to make the Queen keel over and die, then perhaps now is the time to abdicate and let someone else sort it out. Charles vs. Johnson, anyone? The death or abdication of the monarch would create the mother of all crises, whichever way. (Thanks @SE25A for this one)

And, finally, most implausible of all? This idea, by Mathias: