The Electoral Commission warned there had been “unacceptable abuse and intimidation of candidates,” as well as acknowledging “there is room to improve the experience for some” during voting after the late arrival of postal ballots.

In a statement following the closure of polls, chief executive of the watchdog Vijay Rangarajan said: “Today, tens of millions of people exercised their democratic right and had their say at the ballot box.

"Overall, our initial assessment is that polling day ran smoothly and people were able to cast their votes securely. We continue to support administrators as they undertake counts tonight.

“Millions of people were able to have their say, but we know there is room to improve the experience for some. A record number of postal votes were successfully returned, but some couldn’t vote both in the UK and abroad because of the late arrival of postal votes.

“There was a robust and vibrant campaign, but unacceptable abuse and intimidation of candidates. We will collect evidence from people who participated in these elections as voters, candidates, campaigners and administrators, to better understand their experiences. We will recommend improvements to the systems where necessary.

“Delivering a general election is a considerable task, especially so soon after the May elections in England and Wales. New rules were in place this year, including on voter ID where we saw very high levels of public awareness.

"I want to thank electoral administrators across the country for their dedication and professionalism in delivering these well run polls.”

What does the Exit Poll say?

Sir Keir Starmer will be the next Prime Minister according to the exit poll, which predicts Labour will win 410 seats at the election.

A party needs 326 seats to hold a majority in Parliament.

The second largest party is expected to be the Conservative with 131 seats, while the Lib Dems will be the third largest party at Westminster with 61 seats.

Reform are expected to pick up 13 seats according to the exit poll, while the SNP in Scotland are predicted to return 10 MPs to Westminster.

What is an exit poll?

The exit poll is a way of predicting what may happen in a general election, revealed after voting has concluded but before results are counted.

Exit polls take place at around 144 polling stations across the UK and the information then is used to predict the result of the election.

It involves asking tens of thousands to fill in a private ballot after they voted to get an indication of how they voted in the actual election.

Participating polling stations are usually chosen because they are considered to be demographically representative of the UK as a whole, with a mixture of rural and urban seats selected, and a number of marginal seats also chosen.

How accurate are exit polls?

Prof Sir John Curtice, who leads the team that crunches the numbers broadcast to the nation as the polls close, told the Telegraph: “The record isn’t perfect, but since 2005 the exit poll has given a pretty good indication of where the result will end up on the night.

“It also tends to be more accurate than opinion polls carried out before voting happens.

“We use these replica ballots to make models that predict how constituencies will have voted.

“The data we get from those ballots is compared against how people voted at the same polling station at the previous general election.

“Crucially this shows the geography of how people’s votes have changed. From this, we make a series of equations that indicate who is likely to win each constituency.

“When you add up all these equations you arrive at your final forecast for the whole country.”

At the last general election in 2019, the exit poll predicted an 86 seat Conservative majority, very close to the final outcome of an 80-seat victory.