Before the official results of the 2017 general election filter in an exit poll will be released, providing the first indication of whether Theresa May or Jeremy Corbyn will be heading to Downing Street the following day to form a new government.

What is an exit poll?

An exit poll is based on thousands of interviews conducted outside polling centres across the UK with voters who have already voted. The exit polls at general elections, which are run for the BBC, ITV and Sky by Professor John Curtice of Strathclyde University, have built up a reputation for getting the result right over many election cycles.

The polls work by asking people how they voted at sampling points across the country, and comparing that with surveys at the same places in the previous election. The changes can then be projected to build up a national picture.

What time will it will published?

It will be published at 10pm on 8 June. Section 66 of the Representation of the People Act 1983 prohibits the publication, before the close of the poll, of any forecast, survey or estimate of how people have voted.

How many people are used in an exit poll?

An exit poll is based on thousands of interviews carried out outside polling stations across the UK.

Is it accurate?

Unlike the polls published before a general election, an exit poll involves asking members of the public how they have just voted as the leave a polling station. So, rather than gathering a snap shot of how a voter intends to vote it records how they actually voted. But it is important to remember that exit poll is still a snapshot and not the actual result, which will trickle in throughout the evening and early hours of Friday morning as counts are declared across the country.

Was it right in the 2015?

While there was no exit poll at the EU referendum – as there was no similar referendum to compare with – there was one at the last general election. The exit poll announced when the polls closed at 10pm on 7 May 2015 put the Conservatives on 316 seats and Labour on 239: the Tories ended up winning 15 more and Labour seven fewer.

While this was close the exit polls in the two previous elections - 2010 and 2005 – were spot on.

How many seats does a party need to win?