It is true, as Paul Mason argues, that one day the left will have to move on to Corbynism after Corbyn. In the meantime, however, he now advocates Corbyn without Corbynism – the man without most of the political platform with which he has revived Labour and energised British politics.

Mason presents this as an attack on advisers rather than the leader himself. This is the time-honoured cowardly circumlocution of those who fear to fight but still wish to wound. Politicians should answer for their policies and positions, not staff.

At every level, Mason offers a recipe for the collapse of Corbyn as Leader and the reversal of the changes he has wrought in the party.

How is it rational to respond to an election in which a charlatan promising the hardest-possible Brexit emerged as the runaway winner by proposing to double down on ignoring the 2016 referendum vote?

The nationalistic Brexit party secured more than 38 per cent in the northern region, for example – where Labour holds the great majority of parliamentary seats. To meet this threat by sacking one of these MPs – Ian Lavery – as party chairman, as Mason advocates, would send not just a wrong message to millions of voters, but an actually disastrous one.

It would say, “We no longer care about your views or about having non-metropolitan voices around the table.”

The call to appoint more “young working-class politicians” as Mason advocates is hardly an answer. From Dan Carden and Becky Long-Bailey to Laura Pidcock, Jeremy Corbyn has done just that. I suppose Mason ignores them since they are not banging his Brussels-or-bust drum.

Yes, Labour lost many votes to pro-remain parties too. That was always the danger in an election for which no party was prepared and which voters on both sides of the divide saw as a referendum re-run.

The tallied votes for pro-Brexit and pro-Brussels parties show very little shift in opinion. It does not make sense for Labour to set as the limit of its aspirations trying to corral as much as possible of the 48 per cent who voted remain three years ago.

Mason claims that this is the way to avoid a coup. He is wrong – in fact, it is the coup. It is a capitulation to exactly the same forces, led by Tom Watson, as tried to oust Corbyn in summer 2016.

This time rather than taking direct aim at Corbyn, they take aim at everything he stands for. In a sentence Mason dismisses public ownership and class solidarity as unimportant. He trades in the class struggle, abandoning as lost causes millions of working-class people, for a culture war instead.

Yet it is unclear what side Mason is on in this struggle over values. He writes that Labour “needs to fight personal insecurity, crime, drugs, antisocial behaviour and organised crime as enthusiastically as it fights racism”.

Why put opposition to racism at the end of that sentence – it is the sort of dog-whistling which Farage indulges in? And, indeed, Mason has long argued for restrictions on migration.

Moreover, Mason argues that Labour must stop fretting about imperialism too, just as Trump is stoking up international tensions. This is not so much Corbynism-without-Corbyn as Blairism-without Blair.

It is mysterious how this positioning will play with the progressive metropolitan voters whose concerns Mason sees as central. His “culture war” begins and ends with backing the European Union.

It is as if, having declared a US-style “culture war” Mason wants Labour to play the part of Clinton in the metropolis while embracing Trumpism in the old industrial heartlands. Mason thinks we should tell the youth of the metropolis that those seeking Brexit from our industrial heartlands are misled by a xenophobic and racist endeavour; forsake policies of nationalisation and intervention and instead tell those in our industrial heartlands that they are racists if they believe Europe has played a role in decades of industrial failure and a lack of investment in their futures. I can conceive of no surer way to political collapse.

And does anyone believe for a moment that Jeremy Corbyn would sign up to such a mix of social authoritarianism and foreign interventionism?

This plan would leave Labour speaking to the vast areas of Britain that backed the Brexit Party with the language of the right, playing down our class and transformative agenda, while hoping that progressive voters in London and elsewhere don’t notice so enthused are they by the possibility of remaining in the EU.

And how Mason can claim that “economic nationalism” has been rejected when around 44 per cent of the public voted for parties offering just that, is a mystery.

No, in betting everything on a battle to win votes back from the Liberal Democrats, Mason would strip Labour of everything distinctive and progressive about it – not just key officials who have been marked by their loyalty, but all radicalism on international and social policy and ultimately on the economy too.

In fact, the Corbyn (and Labour) position of appealing to voters on both sides of this new artificial divide into “remainers” and “leavers” is the only way to general election success, and to create a public base strong enough to sustain a progressive Labour government in the teeth of the challenges it will surely meet.

Today is clearly a moment for flinching cowards and sneering traitors. But tomorrow the imperative to preserve and build upon the coalition assembled by Jeremy Corbyn – and, yes, by his advisers – will still be the only future for a socialist project in Britain.

Howard Beckett is assistant general secretary for politics and legal affairs at Unite the Union.