IN Scotland we view the Labour Party through the filter of its disastrous alliance with the Tories during the referendum campaign and Ed Miliband’s embracing of pro-austerity measures during the general election. Result: Scottish Labour is now vying with the local Tories for third place in next May’s Holyrood elections. But down south, Labour has a new anti-austerity leader in Jeremy Corbyn and a new mass membership that has moved the official party considerably to the left. What are Labour’s chances of political recovery longer term? Answer: slim.

To defeat the Tories in 2020, Corbyn needs to transform Labour’s GB poll position – the party does not stand candidates in Northern Ireland. A minimum objective – winning enough seats to block a Conservative Queen’s speech in a progressive alliance with the SNP – would require increasing Labour’s GB vote share by some five percentage points. Which means Corbyn needs to persuade an extra 1.5 million people in England and Wales to vote for him.

On current form, that’s a tall order. At the May election, Labour won 31 per cent of the vote across Great Britain.

The latest opinion polls (with Jeremy Corbyn now leader for just over 100 days) have Labour in much the same place – somewhere between 29 to 33 per cent. Given these same polls vastly over-estimated Labour’s chances last May that is not saying very much.

Where Corbyn has scored is in mobilising a new and more radical membership for Labour – which theoretically means more troops to campaign with and more cash to spend. Labour’s paper membership has jumped from under 200,000 on May 7 to more than 370,000 at the end of 2015 – largely down to the Corbyn “effect”. On top of that there are another 148,000 “associate members” and 112,000 “registered supporters”, who paid £3 to vote in the leadership contest.

True, there has been something of an exodus of anti-Corbyn elements from the party – possibly as many as 30,000 have left Labour since Corbyn’s election. But the bottom line is that Labour has enjoyed an influx of 200,000 new members in just seven months, almost all Corbyn supporters. That makes it possible for him to refashion Labour as an anti-capitalist, anti-Trident party if he so wishes.

Some caveats. First, the Corbyn “effect” does not apply north of the border, where the increase in Labour’s membership is a paltry 4,000. A genuinely social democratic SNP has already scooped the anti-austerity forces in Scotland. And unlike Labour, the SNP is united and able to govern effectively. Those joining Labour in Scotland are most likely former members and unrepentant pro-Unionists still hankering after their old-fashioned vision of a workerist, semi-Stalinist British state.

Second, there is anecdotal evidence that the influx of paper members in England has not actually resulted in any significant increase in Labour activists outside of London. Many who signed up for Corbyn are part of the new generation of clicktivists on social media. Certainly, this group can have a political impact as when they deluged Labour MPs with messages to vote against the bombing of Syria. Labour sources calculate that several dozen Blairites went into the No lobby as a result. But those self-same right-wing MPs are now busily plotting to get rid of Corbyn, something made easier if they still control their local party branches.

These are early days, of course. In Europe, the political tide has started to turn against austerity.The end of 2015 saw big victories for the left in Spain and Portugal. In Spain, the official Labour Party lost ground to the anti-austerity Podemos movement. So can Corbyn win back electoral ground by moving Labour to the left?

One way of assessing Labour’s prospects is to look at real votes cast in the 68 council by-elections where Labour stood a candidate, since Corbyn became leader. In only one region (London) has there been a discernible positive impact, with Labour enjoying a swing of 3.3 per cent. On the other hand, across England there is a pronounced swing against Labour: East Midlands (-5.6 per cent), Eastern (-4.1), North West (-5.5), South East (-2.6), and West Midlands (-10.6). There were too few by-elections in Yorkshire or the North to make a valid assessment.

In Scotland, the swing against Labour averages a whopping -8.8 per cent. In Wales, there is a tiny swing to Labour of 0.1 per cent.

How to interpret these negative results? My guess is that the voters – even those attracted by Corbyn’s anti-austerity stance – are wary of any party that is divided, never mind in the early stages of an existential civil war. No one walking the corridors of Westminster, or sitting in the MPs’ tea room, can have any doubt that Labour is now split into warring factions, each accusing the other of being the death of the party. More than one Labour MP has told me they see this as the start of a process that will end in a general re-alignment of British (English?) politics.

This crisis in UK Labour will most likely play out in a different manner to the SDP split of the 1980s, in which right-wing MPs led by Roy Jenkins abandoned ship before being deselected by their constituencies. Despite the creation of the Momentum group by the new leadership, Corbyn is probably genuine in his opposition to a fresh deselection campaign.

Rather, his plan is to empower the mass membership to make policy (again through social media) and use this to swing the party leftwards, leaving individual MPs to accept or fade away.

Meantime, Corbyn is concentrating his political fire on Labour winning the contest for London mayor, come May. Only in London – which has a significant proportion of the Labour membership – do the Corbynistas have a grip of the party machinery. A win here will consolidate Corbyn’s leadership pro tem – Scotland has already been written off. The bookies have London Labour candidate Sadiq Khan ahead of the Tory (and old Etonian) Zac Goldsmith. Khan is no Blairite but he is more mainstream left than Corbynista. However, pro-Corbyn supporters clearly won Khan the London nomination and his campaign has moved leftwards as a result, promising to freeze tube fares. (Khan might also see himself as an ultimate challenger to Corbyn.)

Yet a leftist Corbynista victory in London – plus another meltdown in Scotland – spells ultimate doom for Labour as a national UK party. Labour could then break up into a Corbynista-London movement and a rival (basically North of England) Traditional Labour Party. Some of the Blairite rump – hated by both emerging Labour parties – will doubtless leech away to fuse with David Cameron’s centrist Tories. If the EU referendum reopens the internal fault lines in the Conservative Party itself – between social conservatives and libertarians, and between Thatcherite free marketeers and One Nation interventionists – then the realignment in English politics will become a free-for-all. Prognosis: the future of party politics in England is viviparous and regionally-dominated. Which leaves Scottish Labour well and truly in limbo.

Meanwhile, north of the border, the focus of the opposition parties (especially Labour) is to deride the unity of a broad-church SNP that seeks to navigate Scotland towards self-government while defending progressive values. Run that by me again, Kezia?