Britain voted Thursday in a general election widely expected to hand the opposition Labour party a landslide win and end nearly a decade and a-half of Conservative rule.
The first national ballot since Boris Johnson won the Tories a decisive victory in 2019 follows Prime Minister Rishi Sunak's surprise call to hold it six months earlier than required.
His gamble looks set to backfire spectacularly, with polls throughout the six-week campaign -- and for the last two years -- pointing to a heavy defeat for his right-wing party.
That would almost certainly put Labour leader Keir Starmer, 61, in Downing Street, as leader of the largest party in parliament.
Centre-left Labour is projected to win its first general election since 2005 by historic proportions, with a flurry of election-eve polls all forecasting its biggest-ever victory.
But Starmer was taking nothing for granted as he urged voters not to stay at home. "Britain's future is on the ballot," he said. "But change will only happen if you vote for it."
Voting began at 7:00 am (0600 GMT) in more than 40,000 polling stations across the country, from church halls, community centres and schools to more unusual venues such as pubs and even a ship.
Sunak was among the early birds, casting his ballot at his Richmond and Northallerton constituency in Yorkshire, northern England. Starmer voted around two hours later in his north London seat.
"I just moved back from Australia and I've got the feeling that everything has turned wrong in this country and a lot of people are not satisfied," said Ianthe Jacob, a 32-year-old writer, after voting in Hackney, east London.
In Saint Albans, north of London, 22-year-old student Judith told AFP: "I don't really trust any of them but will vote. A lot of my friends feel the same."
Voting closes at 10:00 pm (2100 GMT). Broadcasters then announce exit polls, which typically provide an accurate picture of how the main parties have performed.
Results from the UK's 650 constituencies trickle in overnight, with the winning party expected to hit 326 seats -- the threshold for a parliamentary majority -- as dawn breaks Friday.
Polls suggest voters will punish the Tories after 14 years of often chaotic rule and could oust a string of government ministers, with talk that even Sunak himself might not be safe.
That would make him the first sitting prime minister not to retain his seat in a general election.
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"I appreciate people have frustrations with our party," he conceded on Wednesday. "But tomorrow's vote... is a vote about the future."
Sunak, 44, is widely seen as having run a dismal campaign, with anger over his decision to leave D-Day commemorations in France early the standout moment.
In new blows Wednesday, The Sun newspaper switched allegiance to Labour -- a key endorsement given the tabloid has backed the winner at every election for several decades.
It follows the Financial Times, the Economist and The Sunday Times as well as traditionally left-leaning papers The Guardian and The Daily Mirror, also endorsing the party.
Meanwhile, three large-scale surveys indicated Labour was on the brink of a record victory, with the Tories set for their worst-ever result and the centrist Liberal Democrats resurgent in third.
YouGov, Focaldata and More in Common all projected Labour would secure at least 430 seats, topping the 418 under Tony Blair in 1997.
The Conservatives could plunge to a record low of less than 127, the trio predicted.
The Lib Dems were tipped to scoop dozens of seats -- up from their current tally of 15 -- while Nigel Farage's anti-immigrant Reform UK party was set to win a handful.
YouGov and More in Common both forecast the Brexit figurehead would finally become an MP at the eighth time of asking.
If the predictions are accurate, Sunak will on Friday visit head of state King Charles III to tender his resignation as prime minister.
Starmer will meet the monarch shortly after to take up his invitation to head the next government -- and become prime minister.
The Labour leader will then travel to Downing Street -- the office and residence of British leaders -- where he would be expected to deliver a speech before making ministerial appointments.
It would cap a remarkable political rise for the former human rights lawyer and chief prosecutor, first elected an MP in 2015.
He has promised a "decade of national renewal" but faces a daunting task revitalising creaking public services and a flatlining economy.