The Brexit vote reached, like the hand of some invisible medieval executioner, right into the guts of progressive Britain, and pulled something vital out. People reported feelings of loss, trauma and betrayal. The life chances of their kids were altered; their identity challenged; their feelings of basic trust and solidarity with fellow Brits they thought they understood eroded.

Well, now you know what it felt like to be working class in the 1980s. Thatcherism destroyed not just the industry our communities were based around, but our social continuity. The pub where I drank my first pint was the same one in which my grandfather drank his. It has gone, together with the resilient solidarity that kept our violence low-key, our crimes rare, and wages high.

So, if you’re feeling like your future has been stolen by Brexit, welcome to the club. First, a left based on workplace organisation and what Eric Hobsbawm called “a common style of proletarian life” was destroyed; now, thirty years later, a left based on multiculturalism, the rights of the European citizen and liberal social values is ­similarly besieged.

And there is a common thread. If Brexit marks the beginning of a second great disruption in the left’s living memory, then, like the first, its origin lies in the systemic crisis of an economic model. In the 1980s, the elite decided that unions and social cohesion had to be smashed because Keynesianism no longer worked, and organised labour stood in the way of the right’s determination to build a new precariat.

In turn, Brexit happened because neoliberalism no longer works. The right will now use the self-inflicted crisis to attempt, one final time, to make it work, using deregulation, precarity and repression.

But this second crisis has come at a time when the left in Britain is weaker. Not in numbers: the mass influx into Jeremy Corbyn’s Labour Party and the social-democratised Scottish National Party testifies to high levels of engagement and understanding that the crisis demands a fightback. The weakness lies at the level of ideas, strategy and a coherent project. You can observe it everywhere as a series of ­mistimed gestures: the rudderless opportunism of that generation of faux-left shadow ­cabinet members who deserted Corbyn; the huge swing of the Scottish left salariat from ­Labour to the SNP; the “conscience vote” for the Greens which delivered 11 Labour target seats to the Tories, and helped ensure their majority. Above all, in the disengagement from official politics common among a young generation otherwise passionately engaged with social justice and liberty.

Since the morning of Brexit, which triggered the anti-Corbyn coup, many on the left have been mesmerised by Labour’s inner party struggle. However, it is only a reflection of the bigger challenge.

Leave won because it fostered a plebeian social movement. If you go into a small-town railway station and find that the men and women selling the train tickets are having a loud public conversation about how “you can’t use the word ‘gollywog’ any more”, and how you’re “not allowed to buy your granddaughter pink toys”, nobody needs to mention Europe.

Whether the Ukip vote stays firm now, or splits back to its Tory and Labour origins, for a few brief weeks, plebeian resistance to the EU became a self-sustaining meme of resistance.

For some people, it was the first political thing they ever did: they discovered agency and they won. They reclaimed public space for the right to stigmatise migrants and flout the conventions of political correctness imposed by corporate life. The experience will stick with them for a lifetime.

The left can and must revive itself in the same memetic way: as a social movement rooted in the values and lifeworld of global modernity.

There is no longer a “common style of proletarian life”. But there is very tangibly a common style of progressive life, and it stretches across the salariat and the precariat. It reaches from the dance floors of Ibiza to the Deliveroo picket line.

It’s about tolerating difference, about kindness and restraint. It values arguments based on evidence more than emotion. It accepts the “weak ties” sociologists observe in the post-proletarian workforce and builds out of them a social life based on networks, not hierarchies.

It accepts, in a way our grandfathers would have found hypocritical and intolerable, the self as the centre of the world: it understands work on the self as a contribution to collectivity – because if we all have better, less angry, more educated selves, the society we build will cohere without any need for rigid hierarchies. And its concept of human liberation is based more on freedom than on economic well-being.

Because of this, its instinctive response to the crises of the early 21st century was to accept the altermondialiste dictum “One no and many yeses”. But since 2008, the crisis of the neoliberal model mean this is unsustainable. The Spanish Indignado movement of 2011 became a party by 2014 and now runs three big cities. Look at the people tapping away on laptops at Momentum’s temporary HQ in Euston, London, and you see people who, in 2011, were the toughest exponents of the hand-twinkling horizontalism during Occupy. It’s been the same with the Bernie Sanders movement.

But if the horizontalist generation of the left has now “got politics”, it has not yet totally understood the dangers facing it.

Right now, the world economy is being kept alive by money-printing, property bubbles and a probable secret pact between central bankers to avoid rival currency depreciation. The price is higher inequality, stagnation and collapsing productivity.

If we do not abandon neoliberalism, it will create – in the same way as it created the plebeian Leave movement – nastier iterations of the same thing until, one by one, the world’s democratic institutions are eroded and the global order fragments.

That is the precipice on which the progressive generation stands, but they can barely see it. It’s easier to believe that there is a technocratic solution to everything; that activism can be compartmentalised; and – except for the real hardcores or through slip-ups – that political choices don’t have drastic personal consequences.

This technocratic illusion in turn breeds a timeless attitude to historic events. There is scant understanding among the progressive young – and I mean here the very wide, gig-going, eco-friendly, leftish generation aged between 18 and 35 – of two things the 1930s taught the left.

First, that the right side does not always win. The Spanish Civil War was the wake-up call in the 1930s. Though only a few thousand Brits went to fight there, several million realised by the end of it that you can be both morally and politically right and still get killed in a ditch.

Second, that you get very few second chances. Maybe the 1,000 to 3,000 people who voted Green in Labour-Tory marginals in 2015 really were indifferent as to whether David Cameron or Ed Miliband became prime minister. I doubt it. It was a luxury vote, cast on the assumption that somebody else at some future date will rectify any bad outcomes.

You see the same historical insouciance in the actions of Scottish Labour during ­Better Together: the assumption that no matter how many lies, threats and manoeuvres you execute on behalf of the British elite, your mass base will forget about it and revert to deference.

The left in Britain has some clear but time-limited chances.

The first is to reunite Labour around whoever wins the leadership and take the fight around the 90 per cent of issues the party’s left and centre left agree on to a public crying out for a competent opposition. The Labour activists pledging to rerun the coup as an annual outing until the party is destroyed are playing with fire. If there is no viable Labour Party, the space will be open for plebeian racism and xenophobia.

The second lies in Scotland. Two-thirds of the SNP’s members joined after the 2014 independence referendum and their typical profile is left, globalist, ex-Labour. Brexit poses a threat to Scottish nationalism’s very existence – and the progressive cultural renaissance that surrounds it. At some point Scotland will have to stop simply asking for independence and EU continuity and begin to fight for it. Otherwise, as under the perennially flaccid Convergència i Unió parties of Catalonia, the aspiration for radical, progressive independence will wither.

The third chance lies in action from below. When people talk of Labour becoming a social movement they must realise what that means. Frances Fox Piven, the veteran US sociologist, described what a social movement does, based on her study of the early civil rights actions of the 1960s. It causes “commotion among bureaucrats, excitement in the media, dismay among influential segments of the community, and strain for political leaders”.

They want to frack our countryside? Then cause commotion. They want to ration access to the NHS? Then don’t leave it to the junior doctors: fill the admin offices of the health bureaucrats with patients demanding treatment now.

But we have to focus. We, the British left, stand right in the headlights of an oncoming train. It is here, in the UK, that rich-world globalisation took its first hit. If the Labour Party is struggling to stay whole, and if the Union of Great Britain itself looks fragile, then probably many other aspects of the given social order are weak as well.

We may have only a limited time in which to do this. We need a social movement with a few clear messages, whose aim is to invest communities of despair with messages of hope and resistance.

Paul Mason is a former economics editor of “Newsnight” and “Channel 4 News”. His most recent book is “PostCapitalism: a Guide to Our Future” (Penguin)

This article is part of a New Times collection of the future of the left. Read the other pieces here.