Exit polls are of significant importance in the UK electoral process. They mark a key moment when a thorough analysis by a panel of experts reveals the winning trend.
The exit poll is usually published at around 10pm on election night, when voting closes, thereby lifting the media blackout imposed by UK broadcasting rules. This publication provides a wealth of information for the media to analyse.
Unlike other polls, the exit poll is funded by a consortium comprising the BBC, Sky News and ITV. The data is collected by Ipsos and analysed by experts at a centre in London.
Ipsos has conducted exit polls at every UK general election since 1997. An exit poll is distinct from the predictive polls published during the election campaign.
It intercepts voters as they leave polling stations and asks them to fill out a mock ballot paper. Ipsos places its teams in more than 130 polling stations across Britain to provide a detailed, high-quality picture of voting trends, enabling accurate seat projections.
Typically, predictive polls project voter turnout and seats by asking people about their voting intentions. However, these are approximations based on respondents' accuracy in predicting their behavior and on various statistical options.
The exit poll, on the other hand, is based on the actual behaviour of voters who go to the polls at 100 to 150 selected polling stations. Ipsos field workers count voters and ask them to fill out replicas of secret ballots, which are then examined to check for changes in voting over the course of the day. This method provides a more accurate prediction as it reflects actual behaviour rather than intentions.
Historically, exit polling has been highly accurate. In 2019, it was off by just three seats in favour of the Conservatives. It slightly overestimated the forecasts for the Scottish National Party and the Liberal Democrats, but the overall result closely matched the final result. In 2017, it was off by four seats in favour of the main parties. In 2015, it correctly predicted the unexpected victory of the Conservatives, prompting an investigation into the polling industry.
There have been notable mistakes, such as in 1992 when exit polls incorrectly predicted a hung parliament. However, they generally give a good idea of the outcome of elections.
While exit polls provide an early indication of the outcome, there is always some uncertainty, especially in years with significant changes, such as the 2024 election with its new electoral boundaries. The complexity of tracking vote changes in newly drawn electoral districts adds to this uncertainty.
For those eager to know the results, it is possible to watch the exit poll at 10 p.m., go to sleep and wake up at 3 a.m. to see the progress. However, with the excitement of a historic election, it may be preferable to stay up all night so as not to miss anything.
