Boris Johnson's gamble on a snap election looks set to have paid off with the Tories likely to win a sizeable majority, according to an exit poll.
The BBC/Sky/ITV poll suggested the Conservative would win 368 seats, 42 above the 326 needed for an absolute majority in the House of Commons.
Labour is predicted to win 191 seats, the Scottish National Party 55, Liberal Democrats 13, the Brexit Party none, Plaid Cymru three and Greens one.
This would give the Tories a majority of 86.
The Prime Minister greeted the poll by tweeting: "Thank you to everyone across our great country who voted, who volunteered, who stood as candidates. We live in the greatest democracy in the world."
If borne out by the actual results, Mr Johnson will return to Number 10 on Friday with a considerable majority which will, in theory, enable him to drive through his Brexit deal and take the UK out of the European Union next month.
It would represent the largest majority for a Conservative leader since Margaret Thatcher in the 1980s.
The result will be seen as a triumph for his tightly-controlled election campaign, which was largely gaffe-free until the final week.
Thank you to everyone across our great country who voted, who volunteered, who stood as candidates. We live in the greatest democracy in the world. pic.twitter.com/1MuEMXqWHq
- Boris Johnson (@BorisJohnson) December 12, 2019
It will, however, be a significant set-back for the Labour leader Jeremy Corbyn, who will have twice led his party to defeat at the polls.
Mr Johnson entered the election without a majority – having just 298 Tory MPs – after some quit the party and he withdrew the whip from others when they rebelled over Brexit.
Labour, who had 243 MPs when Parliament was dissolved last month, is forecast to have lost 52 seats.
Such a poor result would be the worst for Labour in terms of seats since 1935 and would put extreme pressure on the party's leader to stand down after losing a second General Election in a row.
In a tweet sent as the polls closed, Mr Corbyn thanked activists.
"You're the heart of our party, and you have campaigned tirelessly to win so we can a build a fairer country. I thank you all."
I promised @UKLabour would run the biggest people powered campaign our country has ever seen.
And you, our members and supporters, have done just that.
You're the heart of our party, and you have campaigned tirelessly to win so we can a build a fairer country.
I thank you all. pic.twitter.com/Pic0pw9FCU
- Jeremy Corbyn | Vote today 🌹 (@jeremycorbyn) December 12, 2019
The pound soared against the dollar and the euro as the exit poll emerged. A pound was up 1.85% to 1.342 dollars and up 1.09% to 1.202 euros within minutes of the announcement.
Shadow chancellor John McDonnell said the exit poll was "extremely disappointing", adding that Brexit had dominated the campaign.
And shadow international trade secretary Barry Gardiner said it represented a "devastating result for us" and "all the people who were really needing a Labour victory to improve their lives".
Asked if his party needed a new leader, Mr Gardiner said: "These are things that will be discussed by the leadership of the party in the next few days."
A Labour spokesman said it was still "too early to call the result".