Where could the future of the UK be won and lost, and are any of the party leaders under threat in their own constituencies?
It's being described as the UK's most crucial and unpredictable general elections in decades.
In a bid to break the deadlock over Brexit in Parliament, UK Prime Minister Boris Johnson sent Britain to the polls for the first December election since 1923.
But as voting is underway in Britain's snap general election, what are some of the key seats to keep an eye as the results come in?
Uxbridge & South Ruislip
Prime Minister Boris Johnson enjoys a surprisingly small majority in his own seat of just 5,034 (10.78%), and he could face the threat of a large Labour vote from students at nearby Brunel University. However, a Conservative leader has not been unseated since Arthur Balfour in 1906, and it is unlikely he will be forced to resign.
The leader of the pro-Remain Liberal Democrats, Jo Swinson, will have to defend her seat from the Scottish National Party, who have targeted her majority of 5,339 votes.
Euronews’ Orlando Crowcroft is reporting live from East Dunbartonshire throughout the evening.
Esher and Walton
Former Brexit Secretary and current Foreign Secretary, Dominic Raab, is defending a strong majority in his Surrey seat, but many polls predict that he may be the biggest name to fall this election, with the Liberal Democrats favourite to replace him.
Cities of London and Westminster
Former Labour MP and shadow minister Chuka Umunna is now standing for the Liberal Democrats, hoping to unseat the Conservatives, who held a majority of just 3,148 in 2017. This constituency voted remain in the 2016 referendum by nearly 72% and will be an indication of how successful tactical voting has been if the Lib Dems pull off a shock gain.
Nigel Farage has installed the Brexit Party’s most senior candidate, Richard Tice, in the hope of triumphing over the Labour Party in a constituency which voted Leave in 2016. If they fail in this seat, it is unlikely the Brexit Party will take any of the 274 constituencies they are standing in.
While the Green Party of England and Wales held only one seat in 2017 (Brighton Pavilion), Bristol West might represent their best hope of a second, after a year of elections across Europe that has seen gains for the Greens. The Labour Party currently hold a strong majority.
This was the seat of the outgoing Speaker of the House of Commons, John Bercow, and has not been contested since 2005. This is another Conservative seat targeted by the Liberal Democrats.
Expected to be one of the closest seats in the election, Belfast North is currently held by Nigel Dodds of the Democratic Unionist Party (DUP). Sinn Fein are hoping to take advantage of the slim 4.53% majority after other parties stood aside in this constituency.
Former Cabinet minister Amber Rudd is standing down in Hastings, a seat where she held a majority of just 346 votes as a Conservative candidate. In September, Rudd resigned from the party to protest Boris Johnson’s Brexit policy, and the Labour Party will be hoping to gain this crucial seat in the South of England.
North East Fife
This seat was the most marginal of any across the UK in 2017, with just 2 votes giving the Scottish National Party a majority over the Liberal Democrats.
The best of the rest
Bishop Auckland – a seat which Theresa May had targeted as Conservative leader in the 2017 election. Labour hold a narrow majority of just 502 seats.
Broxtowe – Anna Soubry, leader of the Independent Group for Change, is trying to defend her seat after defecting from the Conservative party since the last election.
North West Durham – regarded by many as Labour’s biggest risk to the Conservatives
Richmond Park – a marginal seat that has changed hands between the Liberal Democrats and Conservatives in recent elections
Sheffield Hallam – former Liberal Democrat leader Nick Clegg lost his seat to Labour MP Jared O’Mara in 2017, who himself is no longer standing