By Lewis Goodall, political correspondent

Imagine the undergraduate history essay questions in thirty years' time.

"How and why did Jeremy Corbyn, a backbencher socialist with no experience of government, become prime minister of the United Kingdom in December 2018?"

The plucky, probably by then boringly abstemious students of the 2040s might offer a platter of answers: the financial crash of 2008, Eric Joyce's fist and the ensuing Labour leadership rules changes which followed the collapse of the mainstream social democratic left as an intellectual force.

The less ambitious of them might offer another no less important factor: luck.


Jeremy Corbyn might be the luckiest politician of his generation.

The Labour politician in the right place, at the right time - when the thirty-year Tory European civil war finally broke them.

It has become cliche to say no one can predict anything in politics these days.

So let me offer not a prediction but a theory: Jeremy Corbyn could be prime minister by Christmas.

There are no ends of potential outcomes to the Brexit morass.

Each seems as unlikely and as likely as the last.

But there is a scenario which, if the cards fall right, Mr Corbyn could enter Number 10 without so much trouble as even an election.

Everything would have to go right for him - but then, it has done before.

Jeremy Corbyn might be the luckiest politician of his generation. The Labour politician in the right place, at the right time - when the thirty-year Tory European civil war finally broke them.

Mr Corbyn has not only timing on his side but the sweet serendipity of a piece of legislation little scrutinised when it was passed - the Fixed-term Parliaments Act of 2011.

Introduced for no other reason than to assuage the Liberal Democrats' coalition anxieties, it has had a massive effect on our constitution and the Brexit process.

The provision which could benefit Mr Corbyn most is the following: in the old days, it was very clear what would happen if a government lost a vote of no confidence.

In post-war history, if a prime minister lost such a division, his or her government would resign and trigger a general election.

That's what happened in 1979 when Jim Callaghan's government fell by a single vote.

That has now changed.

Image: Jeremy Corbyn, left, has spent much of his political career as a backbencher

Thanks to the new act, if a government loses a vote of confidence, that administration does indeed fall - but then there is a two week grace period where another government can be formed before there's an early election.

There is much ambiguity about what that means in practice.

But there is a scenario where Mr Corbyn can use it to seize power.

Imagine the situation: Theresa May loses her Brexit vote.

She clings to power attempting to assemble another, but Labour table a motion of no confidence in the meantime.

She isn't challenged because in the chaos, most Conservative MPs don't wish to make it worse.

Tory MPs rally around - but the DUP at the last moment choose to vote against the government as a signal of their fury at the PM's intransigence over the Irish backstop.

Image: DUP leader Arlene Foster is frustrated over Mrs May's intransigence over the Irish backstop issue

Ironically this would become more likely if the PM only loses the deal vote narrowly (or certainly if she wins it).

If it looks like the deal could come back and pass (aided by a plummeting sterling and stock markets) then the DUP will be forced to act and head it off at the pass - including voting down the government if necessary.



On the face of it is hard to imagine the DUP aiding the Republican friendly Mr Corbyn and Mr McDonnell to Number 10 - but if they have no choice, they will.

Because at that point, what will pose a greater threat to unionism in Ulster will not be a weak Labour government led by Republican Corbyn but the deal, with its perceived threat of sucking the province into the Republic's political and economic orbit.

Ultimately, the threat to unionism of a Mr Corbyn government is rendered largely neutral by the Good Friday Agreement and its provisions, with which they are largely content.

Image: Jeremy Corbyn could replace Theresa May if she loses a no confidence vote

That is not so with the deal.

And so it is striking how similarly they've been echoing the language of Mr Corbyn's Labour on Brexit, of late.

If the DUP came onside and if every other opposition MP voted against the government then the numbers would be there.

With no majority of her own Theresa May would have nothing to shield her.

That is where the ambiguity begins to aide Mr Corbyn.

It isn't clear from the Fixed-term Parliaments Act exactly what happens during the grace period - whether or not the Tories (possibly with a new leader) have the right to try and form a government or whether the opposition parties do instead.

Corbyn: Second Brexit vote 'option for future'

If May lost a confidence vote - and with the Tories unable to elect a new leader in time - Jeremy Corbyn would have a strong claim to be summoned by the Queen to try and form an administration.

And he would make it.

This whole situation will give Buckingham Palace nightmares, given it would place the sovereign in a difficult political position.

But that itself has happened before - when the Queen had to exercise discretion in calling for Harold Wilson in 1974 after Ted Heath failed to form a government despite having more seats.

But the FTPA adds an extra layer of complication leaving us in uncharted constitutional territory.

Clearly a Corbyn government wouldn't last long.

An election would surely follow soon after his ascension, as the rainbow coalition of opposition parties propping him up would surely not endure.

But the biggest problem for the Labour leader is that people can't imagine him as prime minister, and that would be over at a stroke because he would be.

Sky Views is a series of comment pieces by Sky News editors and correspondents, published every morning.

Previously on Sky Views: Adam Parsons - Sky Views: Reporting facts is not scaremongering