It’s Tory remainers – not Labour leavers – who are the real key to this election

A third of 2017 Conservative voters also voted remain. Will fear of Jeremy Corbyn keep them away from the Lib Dems?

The first week of campaigning is behind us and the shape of the election is emerging. The critical questions for the next four weeks and beyond are becoming clearer. Among these is whether this election will accelerate a realignment of British politics based on where voters stand on Brexit. The idea that old political tribes are dying has taken hold and increasingly commentators look to the cultural polarisation seen in the US as the trajectory we are following. But, as we've learned over the past five years, things are rarely that simple in British politics. The general election is about much more than just Brexit: a winter election brings different factors to the front, not least the potential for disruptive weather events, such as the devastating flooding experienced by parts of Yorkshire and Derbyshire last weekend, and the additional strains on a stretched NHS.

Despite the apparent strength of newly forged Brexit identities, they are of little use in understanding how people might react politically to other factors; they simply do not allow us to read off a person's political views across a range of issues.

The 2017 election saw the highest two-party share of the vote for three decades. The electorate in England was largely sorted between the Conservatives and Labour, but there are important groups within each cohort who are not aligned with their parties' respective positions on Brexit. We have heard recently about the "red wall" of Labour leave seats crossing the country through South Yorkshire and the West Midlands, symbolised farther north by the "Workington man". Among Labour party voters in 2017, about three in 10 voted leave. We have heard a lot about them over the past three years. They are left-leaning voters who are socially conservative and who had been falling out of love with Labour for some time. More will be written about them in the weeks to come. But there is another group of voters who are also "cross-pressured" in the same way and are perhaps even more cast adrift by their party in recent months: among those who voted Conservative in 2017 a similar three in 10 voted to remain in the European Union. We have heard less about this group, but they could also be key to the parties' fortunes.

Who are they, and will they still vote for a Conservative party that has moved further away from their position over the past three months? In the European elections earlier this year (held before Boris Johnson became prime minister) this group were as likely to vote Liberal Democrat as they were to vote Conservative. More recent polling for the Westminster election suggests that this is a very different competition. Here, those intending to vote Conservative among this group outnumber those intending to vote Liberal Democrat by more than two to one. That said, this group is also more likely than other party/referendum combinations to be undecided, with one in five saying that they had not yet decided how they would vote. Polling this week suggests that Tory remainers are also less certain in their intention to vote Conservative than Conservative leave voters are, or than Labour remain voters are to vote Labour.

Two things stand out about the identities and values of this group. They have weaker remain identities than those remain voters who voted Labour in 2017. Among the latter group, more than half have a "very strong" remain identity while for Conservative remain voters this is less than one in three. They are also the most "rightwing" or economically liberal group of voters in terms of their views on nationalisation, trade union power and taxation. These economic values make this group especially hostile to the Labour party, and "fearful" of a Jeremy Corbyn-led Labour government. Recent polling by Lord Ashcroft found that seven in 10 of this group thought a Corbyn-led government would be worse for Britain than leaving the European Union.

Nigel Farage's decision to stand down Brexit party candidates in Conservative-held seats, and the signal this sends about the positioning of the Conservative party after the election, may give these voters pause for thought. But what the Conservatives are banking on to ensure they hold on to seats such as Putney, south-west London, where the estimated remain vote was more than 70%, is that these voters will be too concerned about a Corbyn-led government, even a minority one, to "risk" a vote for the Liberal Democrats.

Might this change during the campaign? Critical to this will be the expectations people have about what the outcome of the election will be. If Tory remainers expect the result to be close, or if there is even a hint of a hung parliament in the polling, they are likely to be spooked back to the Conservatives at the prospect of Corbyn in 10 Downing Street. But if the polling settles somewhere close to the current levels and a Conservative majority seems more likely, they may feel they are more able to move to the Liberal Democrats to send a message to their erstwhile party that they do not like the direction in which it is moving.

There may be a paradox in this. The more the media narrative focuses on how unpredictable the election is, the less likely these Conservative remain voters are to feel they can safely switch their vote, in the end making the election rather more predictable than it first appears, and forestalling the Brexit realignment.

• Paula Surridge is a senior lecturer at the University of Bristol's school of sociology, politics and international studies