General Election 2024: Understanding exit polls

With just three days left until the General Election, the focus is shifting to the final stage: the exit polls.

Here’s everything you need to know about exit polls in the General Election, how they work and their accuracy.

What is an Exit Poll?

Exit polls are conducted at around 144 polling stations nationwide. Tens of thousands of voters are asked to privately fill in a replica ballot as they leave, providing an early indication of how people have voted.

Where are Exit Polls Conducted?

Fieldworkers from polling company Ipsos Mori visit the same polling stations at each election. These stations are chosen to be demographically representative, including both rural and urban areas, with a slight emphasis on marginal seats.

Polling expert Sir John Curtice explains, “Wherever possible, we return to the same places as last time. The method of the exit poll is to compare the results in the selected polling stations this time with those of the last exit poll.”

How are Exit Polls Conducted?

In addition to identical ballots, a replica ballot box is used to maintain vote confidentiality. Sir John noted, “We use this method to maximise the confidentiality of people’s votes. Asking people directly might make them reluctant to share their choice, so this process helps minimise refusal rates.”

The number of people approached at each station is a “systematic sample,” meaning the sample size varies based on the registered electorate of the area.

How Accurate are Exit Polls?

The accuracy of exit polls has improved over time. In 1974, the first British exit poll predicted a Labour majority of 132, but the actual majority was only three.

In recent elections, exit polls have been highly accurate. Sir John Curtice, a professor of politics at Strathclyde University, said, “They’ve tended to be relatively accurate, not perfect, but often more accurate than opinion polls. This was true in 2015 and 2017 when exit polls provided a better guide.”

What Did Exit Polls Say in Recent Elections?

2015: The exit poll was more accurate than opinion polls, though it did not predict a Conservative majority.
2017: The exit poll correctly predicted the Conservatives would be the largest party, but it did not foresee a hung Parliament.
2019: The exit poll predicted a Conservative majority of 86 seats, very close to the actual 80-seat margin of victory.

As we approach election day, the exit polls will be closely watched, providing a key early indication of the election outcome. Stay tuned for the results shortly after 10.00pm on election night.