Right now, party strategists are squinting at demographic tools that divide Britain into sub-tribes in a battle to woo voters in individual postcodes. But they’re missing the bigger picture. This election is set to be dominated by political divides that are new, and much larger. Instead of micro-demographic categories, what we’ll need to understand are dreams. These can be reduced to three geospatial identities, which I’ve labelled Scandi-Scotland, the asset-rich south-east and post-industrial Britain.

The whole drama of the election rests on the fact that none of the major parties has fully accepted the emergence of these new faultlines, and are still trying to capture a political centre that does not exist.

Let’s start with Scandi-Scotland. If the polls are right, the next parliament will be dominated by the issue of Scottish independence. If you think this was settled in last September’s referendum, you’d be wrong. Large numbers of Scots, even some who voted no, have formed an identity best summed up by the pre-referendum poster that said: “Welcome to the warm south of Scandinavia”. It is left-social democratic in content, but globalist and Europeanist in reach. Whatever the unionist parties say about a coalition with the SNP, the question of whether this dream can be fulfilled within the UK will be crucial.

But that is only a product of the second geospatial fact that nobody wants to talk about: the north-south divide. It’s an old reality but one that has evolved into something harder and more complex. There is a distinct south-east English identity forming around a persistent economic fact: asset wealth. If you look at a map of Britain resized according to house prices, London and the south-east form a massive blob, and every other region and nation are mere stringy offshoots, like a fried egg that is all yolk. Though enlarged by the current house-price boom, this inequality is at least as old as the free-market era and has produced a mindset in south-east England that crosses classes and ethnicities.

People in south-east England understand, implicitly, that they are riding the success of Britain as a financialised economy. They understand that, when this great financial machine is functioning, even as it boosts inequality, the only logical thing to do is find your place in it – whether as a currency trader or taxi driver, lapdancer or legal secretary. Blairism’s insight was to understand this change was underway, and to adapt Labour’s politics to capturing parts of south-east England. The party’s mistake was to believe the change was universal, and that Scotland, Wales and northern England would stay loyal as it made the adaptation.

That they did not has led to the formation of the third geospatial identity: post-industrial Britain. This includes much of northern England, south Wales, many coastal towns and most big cities. Post-industrial does not mean “rust belt”; it means the industries that survive are hi-tech, globally focused and employ a fraction of the staff they used to. But there is a strong self-replicating industrial consciousness; a more hostile attitude to asset wealth; stronger local identities – which become fractious where the labour market is globalised.

Can these three groups exist together in a single political system? During the Scottish referendum, it was clear that many young Scots believed the “aspirational southerner” group in England is more or less permanently aligned with conservatism and liberalism, and can therefore block the left-social democratic government in Westminster that many of them want. They looked at the ethnic tension in northern English towns, the decline of trade unions, the splintering of the Labour vote to Ukip, and concluded that, though the post-industrial group is their natural ally, it can never win a governing majority.

Today, with £375bn of quantitative-easing cash sloshing around, and an avalanche of infrastructure projects focused on London, the south-east group can look in the window of the estate agents and once again feel good. Flattened wages mean the feelgood factor may be weak, but it is as real in Basingstoke as it is absent in Barrow-in-Furness. The only faultline within the south-east identity is generational. The asset-wealth-generating machine is only working for the middle aged and older. Many young people are renting, and are bitter about being locked out of the housing market.

If you look at this election as a contest between three geographically determined dreams, here’s the problem. The only one of these groups plagued by doubt and incoherence is post-industrial Britain. The SNP and the Tories seem to have captured the zeitgeist of their heartlands well. Labour has not. Having spent last week sitting in the clubs and workplaces of Blackpool, Preston and Barrow-in-Furness, I can see the situation is clearly: that even where they’ll vote solidly for Labour, they’ll do so without enthusiasm. Offered the chance to watch Paxman v Miliband, the members of one Barrow working men’s club switched to the rugby league.

So post-industrial Britain feels trapped between two rival but confident narratives that it cannot culturally relate to. Looked at this way, the election becomes a survival battle for Labour. It has to stem losses in Scotland, hold on to the English inner cities and reach into those parts of south-east England where housing economics are blighting the prospects of the young. It’s doable, but still leaves the basic problem intact.

Politics is no longer about finding the middle ground between “two nations”: it’s about three dreams that may be incompatible within the current constitutional framework. That, for all the rhetoric, is what the election will really be about.

Paul Mason is economics editor of Channel 4 News. Follow him @paulmasonnews