Brexit still casts a long shadow over British politics. The main parties try to ignore this. They would prefer to say nothing about it between now and the general election. But its impact persists. The divisions exposed and deepened by the 2016 referendum still affect the way people vote.
The chart below show why. It tracks the Conservative poll lead among Remain and Leave voters, and how the two groups have diverged over the past decade.
In 2015, David Cameron promised a referendum on membership of the European Union and secured a narrow overall majority. The Tories defeated Labour by seven points (38 to 31 per cent) in the popular vote. (All percentages I’m using here refer to Great Britain and exclude Northern Ireland, with its different pattern of party competition.)
However, among people who went on to vote Remain, Labour won by 12 points (42 to 30 per cent). It was the much larger 26-point lead among future Leave voters (47 to 20 per cent) that secured Cameron’s victory.
If anything, that understates the significance of the referendum issue. Ukip won 13 per cent of the national vote, and almost all of them voted Leave a year later. As many as 71 per cent of Leave voters supported Conservative or Ukip candidates in 2015, whereas just 25 per cent voted Labour or Liberal Democrat.
In 2017, when the Tories lost their majority, Remain and Leave voters swung in opposite directions, and with a vengeance. A small overall swing to Labour masked a 4 per cent swing to the Conservatives among Leave voters (as Ukip collapsed), but a 9.5 per cent swing to Labour among Remain voters. Jeremy Corbyn has never liked the EU, but he owed Labour’s advance in that election to Britain’s pro-Europeans.
The “Get Brexit Done” election in 2019 saw further polarisation. Overall, of course, Labour’s result was disastrous. It lost ground on both sides of the Brexit argument. But the modest 3.5 per cent swing to the Tories among Remain voters was far outweighed by the 12 per cent swing among Leave voters—and the crumbling of Labour’s “red wall”.
The latest polls show a dramatic reversal of fortunes. It’s not just the big anti-Conservative swing across Britain that polls have been recording for the past year; it’s that Tory support among Leave voters has collapsed, from 74 per cent four years ago to 40 per cent today. (In last week’s blog, I argued that most polls probably overstate Labour’s true lead. It may well be that the figures for 2024 slightly understate the support the Conservatives would actually achieve, especially among Leave voters. But compared with 2019, its haemorrhage of support is still dramatic.)
Roughly half of their lost votes have gone to the Reform Party; but much of the rest has gone to Labour (up 12 points since 2019) or the Lib Dems (up three). The net effect is a huge 23 per cent swing to Labour among Leave voters—compared with a far smaller (but still significant) 7.5 per cent swing among Remain voters. The chart below compares the results of the 2015, 2017 and 2019 general elections with 2024 polling.
All this gives us a picture of turbulence of a type that, Scotland apart, we have not seen across Britain in recent decades. When the mood has shifted in the past, different groups of voters have tended to move in the same direction. Brexit has changed all that, at least for now.
Three lessons stand out from the ways voting patterns have evolved over the past decade.
Between 2015 and 2019, the Conservatives gained far more support among Leave voters than they lost among Remain voters. Under Boris Johnson in particular, this was a deliberate strategy. It worked.
However, the Tories have failed to convert that very large number of new voters into an expanded electoral base. Until 2019, the shadow of Brexit left Labour in the dark; today, the growing belief among Leave voters that Brexit has failed is the shadow that darkens Tory prospects. Buyers’ remorse has moved many of them to Labour, while Reform has picked up votes from those who want a harder Brexit than they have been given.
Finally, and worse still, the Tories have paid a steadily growing price among Remain voters. The party that took Britain “into Europe” 50 years ago had only 30 per cent support among Remain voters in 2015—when, of course, Cameron wanted the UK to stay in the EU. That support fell further in 2017, failed to recover under Johnson and has fallen further to just 17 per cent today.
We have yet to see how things work out when polls are replaced by real votes in a few months. But here’s one possibility. Maybe, in years to come, we shall look back at the past decade as an era in which they have paid a long-term price for short-term triumph. As things stand today, they have failed to hold on to their surge in support from Leave voters—and become increasingly toxic to pro-Europeans. The result has been to shrink their traditional, ideologically broad, electoral base and threaten their ability to win future elections. They have created this problem in the past decade. Will they be able to solve it in the next decade?
