Prime Minister Boris Johnson on Friday said the British people had given his Conservative government a "powerful new mandate" to deliver Brexit and unite the country.
Exit polls and early results suggest the Tories are on course for a historic victory in Thursday's election, in which Johnson won his own seat in Uxbridge, west of London, with an increased majority.
The Conservatives were forecast to win a thumping 368 out of 650 seats in the House of Commons – which if confirmed would be the party's biggest majority in three decades – according to the survey published as polls closed.
The pound jumped by about two percent against the dollar on the projected results of what all sides had painted as the most momentous election in Britain in a generation.
"We knew he was incapable of leading. He's worse than useless," said former Labour home secretary minister Alan Johnson.
If confirmed, it will be Labour's fourth successive electoral defeat – and the second under Corbyn -–which could see the party out of power until 2024.
The anti-Brexit Liberal Democrats were also heading for a disappointing night, forecast to win just 13 seats, one more than they won in the election two years ago.
They performed well in European Parliament elections earlier this year, but new leader Jo Swinson failed to make an impact and experts suggest her promise to reverse Brexit without even a new referendum was unpopular.
Hopes also appeared to be dashed that "Remainers" would vote tactically to secure a second referendum.
By contrast the Scottish National Party (SNP), which wants to stop Brexit and deliver an independent Scotland, was forecast to win 55 of 59 seats available.
Former Scottish Conservative leader Ruth Davidson had pledged to swim naked in Loch Ness on New Year's Eve if the nationalists won 50 seats.
Johnson remains a polarising figure in Britain thanks to his leading role in the 2016 EU referendum vote for Brexit, which was marked by anti-immigration, populist rhetoric.
But he has again proved his ability to appeal across political lines, as he did when he was mayor of London – aided by a simple message on Brexit.
Eurosceptic leader Nigel Farage also claimed to have boosted the prime minister's chances by declining to stand candidates for his Brexit Party in Tory-held seats.
The Brexit Party, like its former incarnation UKIP, is not predicted to win any seats.
Johnson has promised to put his Brexit plan to parliament before the Christmas break, although it will not likely be ratified until January.
He has then just 11 months to agree a new partnership with the EU before a post-Brexit transition period ends in December 2020.
But with a comfortable majority in parliament, analysts note he could choose to extend that time and negotiate a closer trade deal than previously envisaged.
"Ironically, this is a freer hand for Johnson to negotiate a softer version of Brexit," said Simon Hix of the London School of Economics.