Imagine there was a turkey farm where they were not just being asked to vote for Christmas, but where the turkeys had organised themselves into various groups and each group had different ideas about who’d do better out of Christmas than the other lot; and where they could actually try to move the date of Christmas; and where the rules about voting for or against Christmas were almost impossible to understand in any case.

That’s more or less where the UK is now: a dysfunctional version of the Bernard Matthews estate – stuffed.

The question “When will the next election be?” ought to be easy to answer. It is not. The answer should be “not before 5 May 2022”. Beyond that – in terms of the formal legal position – it is extremely difficult to be, in the buzzword of the moment, “certain”. It is likely to be before 5 May 2022.

In the old days an election could be called pretty much when the prime minister wanted to or, more rarely, a government lost a vote of confidence. That’s how we got Margaret Thatcher, for example. When the Labour government led by James Callaghan lost a vote of confidence on 28 March 1979, that was that. The election was on.

Now, partly because of some systematic abuse of the power by prime ministers engineering pre-election booms, we have the Fixed-term Parliaments Act. This was passed in 2011 by the Coalition Government at the insistence of the Liberal Democrats, and was supposed to weaken prime ministerial privileges by transferring the power to call an election to the House of Commons as a whole. Under this law, an early election (before 5 May 2022) can only be held if one (not both) of these conditions is met:

General election 2017: Irish PM warns May about deal with the DUP

A) If a motion for an early general election is agreed either by at least two-thirds of the whole House (including vacant seats), ie 434 Members out of 650, or without division (ie so unanimous is the House that it can show its opinion with a deafening chorus of “yes” to the Speaker, so that a formal vote would be unnecessary, a nod to old fashioned conventions).

Or, B) If a motion of no confidence is passed and no alternative government is confirmed by the Commons within 14 days by means of a confidence motion.

When Theresa May made her dramatic announcement in the street outside Number 10 on 18 April, it was technically not legally binding, despite the sensation it caused, because it didn’t follow the 2011 Act’s procedures. That was, if you recall, why there was all that talk about whether Jeremy Corbyn would agree to it – because only with Labour votes could the Commons have the two-thirds majority required by law. (It would have been possible for her to propose no confidence in her own government, but that would have been too bizarre for her). Had Corbyn said no to an early election then May wouldn’t have had her bid for a new mandate (if only she’d known what was to follow).

But Corbyn had to agree to an election as the political damage of running away from one, and being seen as cowardly, would be too great. (Shrewdly, the SNP opted to abstain.) Ironically, some commented at that time that Corbyn should have refused to facilitate the 2017 election because it would have smashed the Labour Party for ever and made May invincible. That recent episode also persuaded some that the Fixed-term Parliaments Act was irrelevant; maybe that’s true under a majority government – but it comes into its own viciously when there’s a minority administration, as we are about to discover.

So now what would need to happen to trigger an early election?

The immediate option is for the Prime Minister to pull the rug on her own “certain” pact with the DUP at a time of her choosing – provided all of her MPs and all 10 DUP MPs vote solidly in a vote of no confidence in their own government (more irony, right there). Bizarre, but possible.

That would just be the first step, though. There would then be a period of two weeks in which Corbyn could seek to form a government of his own.

Say he managed to pull off a similar pact to May’s, but instead with the Liberal Democrats, the Green MP Caroline Lucas, the Scottish Nationalists and Plaid Cymru. There is also the possibility, merely theoretical of course, that the DUP could switch sides (but as they despise Corbyn’s past links to Sinn Fein, in this particular instance they almost certainly won’t). Corbyn would even then not command a full majority, and the Conservatives might want to bring him down straight away with the vote of no confidence required within 14 days.

The other crucial factor in such a vote of confidence is how many MPs would abstain from voting. Corbyn would still need some votes from other parties to bridge the 60-seat gap between himself and the Tories (that is if the Tories did intend to vote against him). A Corbyn government’s survival relies on the DUP abstaining, which it probably would not – but they could threaten it now, to maximise leverage over the Tories. That, in turn, might be unacceptable to the other parties and the mainland British voters.

The point here is that votes of no confidence have only to be a simple majority of the votes cast. Corbyn would only need 50 per cent plus one of the votes, not a fixed barrier of 50 per cent plus one of the number of MPs (unlike the two-thirds rule for an early dissolution). Even so, he’d definitely need minority support if the Conservatives were against him.

Even if such events occurred, he might only be Prime Minister for a short time – the 2011 Act isn’t clear on whether May would resign straight away. Still, the logic is that Corbyn would need to face the Commons as Prime Minister in order to debate the motion of confidence in Her Majesty’s government – because that would have to be the current government and could only be the one led by Corbyn, seeing as they'd already passed the motion about May. If he lost, he would be prime minister during the election campaign, because the Queen’s government must continue and there cannot be a vacancy. He would have to stop himself attacking the record “of this government”, because it is technically his own. The irony.

Jeremy Corbyn says there may be another election later this year

Another scenario is that the DUP become disillusioned with May and opt out early, and then vote against her government in a vote of no confidence with every other opposition MP. That would bring her down, and usher in a Corbyn-led government, at least for the short period before it too faces a vote of no confidence (and assuming it loses, which it might not), within a fortnight. Again it probably rests on the DUP abstaining, which makes them kingmakers once again.

So, either way, after May lost her vote, Corbyn could conceivably form a completely go-it-alone minority administration and put forward measures that were timid enough to pass without a vote of no confidence being tabled, or he could brazen it out. This is what he and McDonnell are floating. In such a situation the power of the smaller parties becomes hugely magnified.

Given all that, the Labour and Conservative parties could decide to conspire, as last April, to pass a motion calling for an early poll, just to end the chaos. They’d have to agree to forget the tussle about who gets to be prime minister going into the election and not bother with a series of votes of confidence. Unless they compromised on Tim Farron being “acting” prime minister for a fortnight; this is how odd it gets.

The difficult thing is that, if it is in the party political interest of one major party go for an election – because they have a commanding poll lead – then it is not necessarily in the interests of the other party, who would want to avoid it like hell (though Corbyn was game enough to go for it a few weeks ago). So the two-thirds rule couldn’t work.

Nor, in the alternate case of a motion of no confidence, is it necessarily something the Lib Dems or, say, the SNP would welcome if they felt they would lose more ground by having an early poll. For the SNP, it might mean falling below half the Scottish seats in the Commons – a psychological barrier they clearly fear.

So all the way through the Brexit talks we could be left with permanent chaos.

That, in a way, was the point and the design of the Fixed-term Parliaments Act. It was aimed at cementing the Lib Dems and the Conservatives in a tight coalition government for a full five-year programme, and to minimise the risk that one or other of them would peel off (or an internal faction pull the administration down). The whole idea was to make an early election so difficult to achieve it just wouldn’t happen. You might think that the Fixed-term Parliaments Act was a mistake and a thing “of its time”, and the best thing would be to abolish it: but that would require a majority in the Commons, so could amount to much the same thing.

Yes, the Tories and the DUP could ask Parliament to abolish the Act now, but that would also mean breaching Section 7 of the Act, which requires the prime minister to make arrangements between June and November 2020 for a committee to carry out a review of the operation of the Act. Not binding on the following parliament, that, but something of a brake on a hasty abolition of the Act. The House of Lords (who didn’t like it much in the first place) would also need to be agree, though it is surely primarily a Commons matter.

Abolition of the 2011 Act was in the Conservative manifesto this time round, but the DUP was silent on this issue. Whether it is subject to the Salisbury Convention that states a “winning” party manifesto cannot be blocked is debatable. No doubt someone would try and send it off to judicial review, ironically including to the European Court. You could argue, for example, that the effect of abolition at that moment would be to extend the life of a parliament, contrary to the Parliament Act (the 1911 not the 2011 one). It could get messy.

The other thing to remember is that, under the 2011 Act and previous conventions, a government can lose all manner of important votes – on the Budget, say, or Trident, or Brexit, or the Queen’s Speech – but still not be thrown out if it returns to the Commons and then wins a vote of no confidence (which, by the way, only counts if it is couched in the special wording in the 2011 Act – “That this House has no confidence in Her Majesty’s Government”. If this motion is carried, there is a 14 calendar day period in which to form a new Government, confirmed in office by a resolution as follows: “That this House has confidence in Her Majesty’s Government”. So if the Commons just wanted to blow off steam in a big protest they could pass a motion saying, for example, “That this House has no confidence in the policies of Her Majesty’s Government” or “This House has no confidence in the Prime Minister”, and nothing electoral need happen). In the 1990s, John Major’s government lost loads of votes but he just kept going for a full five year term; it wasn’t much fun for anyone

All of that is just the constitutional rules. Then there’s the politics.

We now have an unworkable situation where the Conservatives’ unspoken but settled public policy is that May will not lead their party into the next general election, whenever it occurs. Therefore they need to organise a leadership election (or the coronation of a successor) in advance of that. Given that the party polls its MPs in exhaustive ballots and then reaches out to the membership across the country over months, that is not a rapid process. In the meantime, the opposition parties are in effect given notice that an election is coming (McDonnell even claims that Labour knew there’d be an election early precisely because May ruled it out last November). In such circumstances party calculation and game-playing become amplified, and not necessarily will they deliver strong and stable administration.

To get a new Tory leader without a bloody battle requires an old one to quit, preferably quietly. Would May oblige? Would she insist on being a candidate once again (as Corbyn did in similar circumstances)? It’s likely she’d not resist, but then again she has a reputation for being “bloody difficult”.

It is a complete shambles and will be for the foreseeable future. It might also drag the Queen into controversy if we find, for example, that the only way of breaking the deadlock would be to revive the Royal Prerogative, explicitly ended in the 2011 Act. Or if she invited Corbyn to form a government when it was plain he’d lose a subsequent vote of no confidence, because the wording of the Act is imperfect. Her courts might have to decide on Her decisions about Her government. That really would be a crisis. In any event, it would not be strong and stable governance of Her realm.

General Election 2017: Big beasts who lost their seats Show all 7 1 /7 General Election 2017: Big beasts who lost their seats General Election 2017: Big beasts who lost their seats Nick Clegg Picture By Darren O'Brien/Guzelian Picture Shows Former MP, Nick Clegg delivers a speech despite losing the Sheffield Hallam Seat. Labour candidate, Jared O'Mara (Front), defeats Nick Clegg to take the Sheffield Hallam seat. picture taken 08/06/2017 Darren O'Brien General Election 2017: Big beasts who lost their seats Gavin Barwell LONDON, ENGLAND - OCTOBER 07: Gavin Barwell MP arrives at Number 10 Downing Street on October 7, 2013 in London, England. British Prime Minister David Cameron announced a Government reshuffle today. (Photo by Oli Scarff/Getty Images) Getty General Election 2017: Big beasts who lost their seats Angus Robertson General Election 2017: Big beasts who lost their seats Nicola Blackwood PA General Election 2017: Big beasts who lost their seats Alex Salmond PA General Election 2017: Big beasts who lost their seats Rob Wilson Mandatory Credit: Photo by Geoffrey Swaine/REX (1096138i) Rob Wilson, Conservative MP for Reading Funeral of Murdered Student Asha Muneer at Rivermead Leisure Centre, Reading, Britain - 28 Jan 2010 Rex Features General Election 2017: Big beasts who lost their seats Ben Gummer Minister for the Cabinet Office Ben Gummer arriving at 10 Downing Street, London for the weekly cabinet meeting. PA

The only stable and certain thing we have to look forward to is that the instability and uncertainty will be permanent. The most terrifying thing is if there was another election and it gave us another hung parliament. This is quite possible, given that there are relatively few swing seats to fight over these days, a modern psephological accident.

The big factors that have moved elections in recent years – the collapse of the Lib Dems in 2015 (which gave David Cameron his majority); the rise and fall of the SNP which helped Cameron and then Corbyn in 2015 and 2017; and the rise in youth participation, which boosted Corbyn – must surely be subject to the law of diminishing returns. A boundary review might tilt things towards the Conservatives, but not for a while (until 2020 at the earliest). So the next election is likely to be tight and, if held in the next year or two, not so very different to the last one. It’s also one which, given the economic crash that is on its way, especially with Brexit, no politician in their right mind should actually want to win: why not let the other lot get the blame? But the Fixed-term Parliaments Act doesn’t say anything about that, either.