Why are voters switching parties more than ever?

Author:
Jessica Garland, Director of Policy and Research

Posted on the 19th December 2024

We recently published our in-depth report on the 2024 General Election, A System Out of Step.

Our polling during the General Election not only revealed the extent of tactical voting under our electoral system, but also the extent to which voters are finding it hard to make the system work for them. With increased voter volatility and multi-party voting – the two-party Westminster electoral system is increasingly out of step with voters.

Voters on the move

Volatility – voters switching between parties – has been a growing feature of UK elections over the last decade.

Volatility can be measured at the aggregate level – how much the national party vote share changes between elections, or at the individual level – the proportion of voters switching party.

The 2024 General Election saw a new record for aggregate volatility, indicating the biggest change in party vote shares for nearly a century. This score beat the previous 2015 record and is only surpassed by the 1931 General Election. The change between elections was also stark with aggregate volatility at the 2024 General Election more than double the figure it was in 2019.

Volatility is partly a result of partisan dealignment with fewer voters holding strong attachments to a single party, but it can also be affected by electoral shocks which change political alignments.

Realignment over the last decade or more has increased the number of ‘cross-pressured’ voters – voters who find themselves aligned with one party on economic issues and with another on social ones. These ‘cross-pressured’ voters are more likely to decide later who to vote for and more likely to switch party between elections, contributing to volatility.

What does this mean for voters?

During the General Election campaign, we asked voters how easy they were finding it to decide who to vote for. While almost two thirds (63%) of likely voters said they had found it easy to make their decision on who to vote for, as many as one in four (26%) said it had been difficult.1Polling for ERS by Savanta (Savanta interviewed 2468 adults between 28th and 30th of June), Question: Thinking about the upcoming General Election on 4th July, to what extent have you found it easy or difficult to make your decision on who to vote for? Base: All respondents likely to vote (n=2,468) Data were weighted to be representative of the UK by age, sex, region, and social grade.

We also asked voters if they had considered voting for another party or candidate. Among those who were intending to vote, almost two in five (38%) said they had considered voting for another party or candidate. This rises to almost three in five (57%) Liberal Democrat voters and half (49%) of Green Party voters.2Polling for ERS by Savanta (Savanta interviewed 2468 adults between 28th and 30th of June), Question: You mentioned that you intend to vote for [Party]. Since the election was announced May, have you considered voting for another party/candidate? Base: All respondents with a voting intention (n=2,302). Data were weighted to be representative of the UK by age, sex, region, and social grade.

For many voters, the difficulty in making a decision is not just about trying to find a party that aligns with their preferences but also calculating whether that party has a chance of winning in the constituency they live in.

Voting with head not heart

Tactical voting has long been a feature of First Past the Post elections. With only one candidate making it across the line, voters are forced to take constituency voting patterns into consideration when making their choice. However, increased multi-party voting and volatility make these judgements more difficult. A range of tactical voting sites have emerged to help guide voters into making an effective tactical vote but of course, not all tactical votes end up working as expected.

We polled voters in the second week of the campaign, going into the final week, and after the election about tactical voting. In all three polls we found at least one in four voters planning to cast a tactical vote: voting for a party other than their first choice to keep out another party they liked less. Two weeks into the election campaign we found that 23% of voters were intending to vote tactically,3Savanta polling for ERS (2,226 UK adults aged 18+ online between 7th and 9th June 2024). Data were weighted to be representative of the UK by age, sex, region, and social grade. Question: You mentioned that you intend to vote. Which of these statements is closest to your reasons for voting for your chosen party/candidate? BASE: All respondents likely to vote (n=1,911). with one week to go this figure was 26%.4Savanta polling for ERS (2,302 UK adults aged 18+ online between 28th and 30th June 2024). Question: You mentioned that you intend to vote. Which of these statements is closest to your reasons for voting for your chosen party/candidate? All respondents with a voting intention (n=2,302). Data were weighted to be representative of the UK by age, sex, region, and social grade. Savanta are a member of the British Polling Council and abide by their rules

Our post-poll research showed that 28% of voters had opted for a tactical vote, similar to the 32% who said so in 2019.5YouGov polling for ERS. Total sample size was 8,426 adults. Fieldwork was undertaken between 8th – 12th July 2024. The survey was carried out online. The figures have been weighted and are representative of all GB adults (aged 18+) and YouGov polling for ERS (fieldwork 13–19 December 2019, online), 8,237 GB adults. Figures weighted and representative of all GB adults (aged 18+).

Ultimately voters should be able to vote for the party who they want to win knowing that their vote won’t be wasted, this is only possible under a system of PR.

Read more in our full report, A System out of Step: The 2024 General Election

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