LONDON — The Brexit culture war is gathering pace — and it is bad news for both the U.K.'s major parties.

According to a new tracker poll of battleground constituencies for POLITICO, Britain’s protracted exit from the European Union is continuing to polarize the electorate, making it harder for Labour and the Conservatives to reach the voters they need to take power at the next election.

With the two main parties all-but tied on around 40 percent of the vote in recent polls, both are chasing two different electoral groups in marginal seats: Leave voters in places like the East Midlands and North West, and Remain voters that dominate London and wealthy university towns.

The problem both parties face is how to appeal to one without alienating the other.

According to the first in a series of POLITICO-Hanbury polls in three clusters of key swing seats, the trends seen at the 2017 general election — with Leave voters moving toward the Conservatives and Remain voters opting for Labour — are continuing as the Brexit impasse continues to grip Westminster.

There is strong evidence that Brexit is playing into a wider British “culture war,” with voters in Leave and Remain areas prioritizing very different values.

The poll results suggest that Leave voters in the East Midlands and North West are moving toward the Tories and away from Labour, while Remain voters in the South East are shifting in the opposite direction.

Among Leave voters in East Midlands, Theresa May’s net satisfaction stands at -2 percent. By contrast, Jeremy Corbyn is far less popular at -69 percent. A similar story emerges in the North West, with May on -11 percent among Leave voters and Corbyn on -59 percent.

Among Remain voters in London, however, May’s net satisfaction is -41 percent, while Corbyn’s is around half as bad at -23 percent.

It means that, as things stand, it will be very difficult for either party to appeal to both Leave and Remain-voting marginals at the same time, opening up the prospect of either a continuing stalemate or sweeping changes to the electoral map as voters base their allegiances less on traditional party loyalties but rather on whichever party best represents the new Leave-Remain dividing line in British politics.

There is also strong evidence that Brexit is playing into a wider British “culture war,” with voters in Leave and Remain areas prioritizing very different values.

Leave voters in the East Midlands and North West, for example, are much more likely to prioritize values like "standing up for common sense and tradition" and "being tough on crime," while Remain voters in London value "being part of an international community’ and "protecting the environment for future generations."

In practice, the electoral battleground appears to be dividing in two — with strong Leave and Remain-voting marginals having vastly different values and priorities.

Voters who favor Brexit are much more likely to view immigration and asylum as a key issue than Remain voters. Only 1 percent and 4 percent of Leave voters in the East Midlands and North West respectively consider "being part of an international community" a top priority, compared to a quarter of Remain voters in London.

Both Remain and Leave voters view Brexit as the top issue facing the country, although for very different reasons.

Asked which issues are the most important facing the country, 40 percent of Leave voters in the East Midlands and 25 percent in the North West said immigration, compared to just 14 percent of Remain voters in London.

According to the poll, 74 percent of Leave voters in the East Midlands describe Labour as “out of touch.” For the Conservatives, just 15 percent of Remain voters in London think the party represents people like them. This jumps to 41 percent of Leave voters in the East Midlands and 29 percent of Leave voters in the North West.

Thirty-four percent of Remain voters in London believe Labour represents people like them, compared to just 20 percent and 21 percent of Leave voters in the East Midlands and North West.

The poll is the first in a series POLITICO and Hanbury will publish this year, tracking public opinion in blocks of neighboring constituencies throughout the country. By creating clusters from constituencies with similar political and demographic features, the aim is to understand what is really happening in some of the key constituencies that will decide the next election.

POLITICO and Hanbury identified four clusters for the series, but three feature in this analysis: the central London seats of Battersea, Putney, Kensington, Cities of London and Westminster, Chelsea and Fulham; in the North West, there's Cumbria’s Morecambe and Lunesdale, Barrow and Furness, Workington, Copeland and Carlisle; and finally the East Midlands marginals of Mansfield, Bolsover, Broxtowe, Amber Valley, Ashfield, North East Derbyshire and Chesterfield.

You can find more detail on the methodology of POLITICO-Hanbury polls here, as well as other polls in the series.