YES March & Rally for Scottish Independence.  Image by Ivon BartOne of the most disappointing things about the independence referendum was the response of large parts of the English left to the Yes campaign.

Although pockets of sympathy existed on the radical fringes of the English commentariat – Tariq Ali, George Monbiot and Anthony Barnett all came out for Yes – the broad consensus, encompassing Observer liberals, Fabian academics and Old Labour social democrats, was deeply hostile.

On the eve of the poll, the Guardian’s Martin Kettle warned against the “dark side” of Scottish nationalism, as though Alex Salmond and Nicola Sturgeon were secret Balkan fascists. A few months before that, in a long, rambling, shallow essay for the Financial Times, Simon Schama bracketed the SNP in with UKIP and Vladimir Putin as “die-stamp patriots … for whom similarity is identity.”

These remarks stung – or at least niggled – because many of us in the Yes camp had expected progressive English opinion to support what we believed to be a fundamentally progressive project. If you had the chance to dissolve a state as constitutionally backward, as militaristic and as socially dysfunctional as the United Kingdom, why wouldn’t you take it?

But we underestimated the loyalty of liberal England both to the Labour Party, particularly in its Blairite form, and to the institutions of British parliamentary democracy. England’s soft-left actually likes the way modern Britain is run, and there’s very little those of us who don’t can do about it.

However, twelve months – and one Labour leadership contest – later, the battle lines are much more clearly drawn. We now know who stands where and why.

The response of progressive England to the rise of Jeremy Corbyn has been every bit as hostile, every bit as snobbishly condescending, as it was to the Yes campaign.

For English liberals, Corbyn and his backers are, like Scottish nationalists, fantasists, extremists, weirdos and cyber-bullies. Never mind that Corbyn was savvy enough to rout their preferred Blairite candidates, nor that independence is fast becoming the majority view among mainstream Scottish voters: if a movement or a party deviates too far from the liberal centre-ground, you crush it – and if you can’t crush it, you use your substantial media resources to ridicule and discredit it.

On a range of key issues, Corbyn and the SNP deviate from the liberal centre-ground.

They will vote together in the House of Commons against Britain going to war in Syria and against the renewal of Trident. They will vote together against further spending cuts and welfare reforms. They will champion more humane immigration and asylum policies. They will oppose Tory attacks on the unions.

The ideological overlap between Corbyn and the SNP provides strong grounds for parliamentary cooperation, but it offers something more than that, too: for the first time in my adult life, Britain has a mass, popular left.

Corbyn’s victory on Saturday wouldn’t have been possible without the tens of thousands of people who joined the Labour Party in order to vote for him, nor the 16,000 volunteers who campaigned on his behalf. These people are England’s Yes voters, motivated by many of the same concerns as Scotland’s Yes voters (which is why, as the prospect of a Corbyn victory grew over the summer, England got its very own Project Fear to combat the Corbyn surge).

Clearly, the sticking point between England’s Corbynista left and Scotland’s nationalist left is independence. Corbyn is a unionist, and that is not going to change any time soon. But his unionism is, at best, lukewarm: the Islington North MP a) recognises the right of the Scottish Parliament to determine Scotland’s constitutional future and b) did almost nothing, as far as I can tell, to help preserve the Union last year.

Moreover, I know that there are supporters of independence in and around Corbyn’s top team; activists, journalists and fellow-travellers who view the events of 2014 as a part of a wider European revolt against a failing economic model.

So it is odd that some nationalists – including, apparently, the First Minister – have chosen to dismiss Corbyn as too weak, and Labour under Corbyn as too divided, to drag English politics onto a more hopeful trajectory. During the referendum, unionists were similarly dismissive of the Yes campaign’s capacity to alter the terms of debate in Scotland. But it did, and nine months later the SNP destroyed the unionist parties at the general election.

Corbyn is not, of course, going repeat that achievement on a British scale in 2020. He may even lose (badly) to the Tories. But as every Yes activist counter-intuitively knows, the long-term foundations of victory can be found in the rubble of defeat.

The goal for the left over the next five years should be to apply the combined weight of Corbyn’s Labour Party and Sturgeon’s SNP to British public opinion, with the aim of breaking the centre’s stranglehold.

In order to do that, leftists on both sides of the border need to identify their enemies and recognise their allies.