The authoritative source for independent research on UK-EU relations

The EU referendum was deeply disruptive for Britain’s two main political parties. Conservative MPs were deeply divided in their preference for Leave or Remain, while Labour MPs blamed their leader, Jeremy Corbyn, for the Remain side’s defeat and mounted a challenge against him. Meanwhile, a majority of Conservative supporters ignored the advice of their Prime Minister and voted for Leave, while around a third of Labour voters went against their party’s advice and backed Leave too.

In contrast, few such difficulties faced the Liberal Democrats or UKIP. Holding a referendum to get out of Europe was UKIP’s raison d’être, and thus an issue on which both the party’s elected representatives and its supporters were united. And while around a quarter of Liberal Democrat voters also failed to follow their party’s recommendation to vote Remain, once the referendum was over the traditionally pro-EU party was soon arguing there should be a second referendum after the Brexit negotiations were completed.

Between them, these developments raised an interesting question. Would the Conservatives and Labour lose support during the course of the Brexit process, as unhappy Remain voters switched to the Liberal Democrats and Leave voters were attracted by the unambiguous position of UKIP. If so, might British politics be fractured yet further?

The general election

At first glance, the outcome of the 2017 election suggests Brexit has had the opposite effect. Support for UKIP imploded to just 2%, lower than in 2005 and 2010, let alone 2015. The level of Liberal Democrat support failed to recover from the 8% to which the party had sunk two years ago. The Conservatives and Labour between them won 82% of the votes cast across the UK as a whole, more than at any election since 1970. It seems as though Brexit has paved the way for a return to the two-party politics that characterised British party politics in the immediate post-war period. However, this conclusion is too simple. Brexit was associated with, and was probably at least a partial cause of, a reshaping of the choice voters made between Conservative and Labour.

Consider, first of all, the trends in party support amongst Remain and Leave voters during the course of the election campaign. In the last four polls conducted by ICM immediately prior to the election being called, 53% of Leave voters said that they intended to vote for the Conservatives, compared with 38% of Remain supporters.

However, this gap widened during the course of the election campaign. In the last four polls ICM undertook before polling day, support for the Conservatives amongst Leave voters was five points higher at 58%, while that amongst Remain voters had dropped five points to 33%. Support for Labour increased across the course of the campaign amongst both Remain and Leave voters. But, at 13 points, the increase was more marked amongst the former than it was the latter (six points).

As a result, what before the election was a 15-point difference between Remain and Leave voters in the level of support for Labour had grown to 22 points by polling day. Evidence that Remain and Leave Britain diverged in their willingness to vote Conservative or Labour is also to be found in the pattern of the election results. With the exception of Scotland, the Conservative vote increased most in those areas that voted Leave, while Labour made most progress in areas that backed Remain.

Within England and Wales, Conservative support increased on average by 10 points in constituencies where, according to estimates
made by Chris Hanretty of the University of East Anglia, Leave won over 60% of the vote in the EU referendum. Conversely, support fell on average by two points in seats where the Leave vote was less than 45%.

Labour, in contrast, saw its vote increase by twelve points in seats where the Leave vote was lowest, but by only nine points in those places where it had been highest. Not the least of the reasons why the Conservatives gained ground most amongst Leave voters and in places where the Leave vote was highest last year is that the party benefitted most from the collapse in the UKIP vote. According to a poll conducted  on polling day by Lord Ashcroft, 57% of those who voted UKIP in 2015 voted for the Conservatives this time, while only 18% switched to Labour.

Equally, where in England and Wales UKIP secured under 7.5% of the vote in 2015, Conservative support fell back on average by three points, while in those seats where UKIP won more than 17.5%, the Conservatives advanced by ten points. The Conservative party is, of course, traditionally the party of middle class voters. But Leave voters were disproportionately working class.

Consequently, it was amongst working class voters and in predominantly working class constituencies that the Conservatives advanced most. According to Lord Ashcroft’s polling data, Conservative support was up twelve points amongst working class “DE” voters than it was in 2015, but by only four points higher amongst professional and managerial “AB” voters. Equally, Conservative support increased by nine points on average in the 30% most working class seats in England and Wales, but by only one point in the 25% most middle class. In short, the divergence between Remain and Leave voters served to cut across the traditional class base of Britain’s two-party system.

What lies ahead?

The general election was, then, more of a Brexit election than immediately meets the eye. Many a Leave voter switched to the Conservatives, while Remain voters were more inclined to back Labour than their Leave counterparts. As a result, the Conservative party in particular won over voters it would not normally be expected to reach. The question that now faces the party is whether it can
keep them as it tries to negotiate Brexit against the backdrop of a hung parliament, in which there will be pressure on the Prime Minister to soften her vision of what Brexit should mean.

By Professor John Curtice, senior fellow at The UK in a Changing Europe. 


Who’s watching local government?

Attitudes towards migration for work remain positive

Kicking the can down the road? The continued precarity of EU pre-settled status

Without the Brexit glue, support for the Conservative Party is coming unstuck

The French elections of 2022: Macron’s half victory in a changing political landscape

Recent Articles