What is going on with Labour, Brexit and the second referendum? On one level it looks pretty straightforward. In recent elections the party lost many more votes to the Greens and Liberal Democrats than to the Brexit party, through paying the price for Jeremy Corbyn’s Euroscepticism and fence-sitting. The simple solution is to guarantee another vote on any deal with Labour as the enthusiastic party of remain in any such contest. This aligns with shifting demographics in the country and a detectable Brexit remorse. What’s not to like?

Media coverage tends to give the impression that the only people who think that Labour should not back a second referendum are a few MPs from somewhere up north who are scared witless by Nigel Farage and their electors, and a couple of Corbyn’s closest aides. So it appears self-evident the party should stop triangulating, offer some leadership and hoover up the votes of remainers.

This argument also interprets the 2017 snap election, when Labour did surprisingly well, as a “Brexit realignment”, in which Labour gained 30 seats and its highest vote share since 2001. It saw a particularly large increase in vote share among younger voters, gained a 15-point lead among graduates and made significant advances in urban metropolitan areas. It held a substantial lead among remain voters and made significant improvements among social classes ABC1. There is no reason, then, not to double down and embrace a new vote.

Opponents of this orthodoxy, and I am one, say Labour needs to retain a longer-term perspective.

Simply put, we have not won a majority since 2005. Sure, Labour lost more remain voters during the course of recent elections; but the party has lost more voters of the kind who voted leave over the course of a generation. And, critically, leave voters are more impactful in the majority of English marginal seats. This debate has become an unresolved numbers game, an internal stalemate, despite the millions piled into polling by the People’s Vote campaign.

In any case, political parties do not just exist to chase votes. They are traditions built around competing theories of justice and democracy; alternative approaches regarding how society should be organised. For Labour, the Brexit dilemma goes to a tension at the heart of the party regarding its character and purpose; even existence.

It is very difficult to see how Labour might create the necessary alliances to gain and retain power

According to the academics Will Jennings and Gerry Stoker, the 2017 election revealed a long-term material divide between those residing in parts of the country that are connected to growing knowledge and cultural economies and those that are not. Using data from 2005 to 2017 they suggest the Brexit vote was related to a long-term class and geographical realignment but did not cause it. If Brexit acts as a proxy for this emerging divide, then simply choosing sides based around an immediate political calculation might trigger epic, unforeseen consequences for Labour. Indeed, some are using the issue to rethink the very nature of the left.

Traditionally, the left’s “base” was the working class. For Marx, it was “the class to which the future belongs”.

Yet recently both the social-democratic and radical left have sought to assert a new progressive “base” A leading advocate of this historic rethink, Paul Mason, recently suggested that “a new strategy must be based on the realisation that Labour’s heartland is now in the big cities, among the salariat and among the globally oriented, educated part of the workforce”. He identifies this as the “new core of the Labour project”, a distance away from the classical left proletariat. The new “base” is to be formed around “networked individuals”residing in “Remainia”.

The argument is that Labour should ditch a sentimental attachment to the notion of a working class based in traditional heartlands; one that electorally offers diminishing returns. The party also suffers from a serious problem of attrition among older voters. The best electoral strategy is to therefore build a future coalition around younger remain voters; a renewal that goes far beyond the repeated search for the “former Labour voter”. There exists a radical new Labour-supporting cultural demographic and a new political geography reflected in the referendum result. Labour should hold its nerve and accept casualties in its traditional seats as we transition towards our new remain heartlands, safe in the knowledge that the working class is dying and increasingly doesn’t vote for us anyway.

For advocates of this position, two key drivers are rewiring progressive politics. First, for 20 years or more, there was much talk of “freedom’s children”, who would entrench a new modernity in the era of globalisation. Parochial attachments were being dissolved, replaced with a radical individualism and strengthened democracy, especially among the more educated and the young. The future would see the desire for “world citizenship” and global political action triumph. The future lay among the post-national, urban, networked, educated youth.

Those on the radical left pronounced the nation dead, given the amorphous power of capital whose modern rule suggested a declining relevance attached to questions of territory and country. For today’s left this has brought forward the political possibilities offered by a transnational multitude to challenge global capital – a radical new form of political agency. The global, urban networked youth have replaced the workers.

Second, the working class is described as being destroyed through automation, leading to an embrace of “post-workerism” and a backing of universal basic income. While future prosperity will be driven by the production of knowledge and intangible assets, the working class, old Labour and the foundations of leftwing thinking are disintegrating. This argument has reappeared today on the radical left with a very specific, optimistic reading whereby technological change destroys the working class and takes us to a vaguely defined place called “post-capitalism”. This political reorientation privileges the urban sites of knowledge work as the means of left advancement. Urban youth is the new left change agent to confront capital. “Networked youth” is destroying capitalism as the information economy is incompatible with the market economy.

As a result of this debate, in Labour today it is increasingly difficult to disentangle the politics around a second referendum – which would divide the party’s leave voters from its remainers – from a conscious strategy to separate progressive politics from the economic emancipation of the traditional working class. Much fashionable thinking tends to neglect the significant role work plays in our lives. It remains a source of dignity and belonging; of overall human wellbeing. Moreover, there are real difficulties with a politics that embraces a global network rather than being anchored around more parochial concerns of place, community and nation. These issues underlie the Brexit challenges the party now faces.

Labour is in danger of privileging certain sections of the electorate at the expense of others. It is very difficult to see how, having redefined the base of the left into such restricted demographic groups, it might create the necessary alliances across classes and geographical settings to gain and retain power. Talk of the “many not the few” cannot cover this up for long.

• Jon Cruddas is Labour MP for Dagenham and Rainham