The Conservatives are on course for a large majority, the broadcasters' official General Election exit poll has predicted.
The poll, which samples 25,000 voters after they cast their ballots, put the Conservatives on 368, Labour on 191 and the Liberal Democrats on 13 - a Conservative majority of 86.
It would be the worst result for Labour if it is correct, worse than the 1983 election when the party won 209 seats under leftwing leader Michael Foot.
Among those forecast to lose their seats is Ruth Smeeth, the parliamentary chair of the Jewish Labour Movement, whose Stoke-on-Trent North seat is predicted to be a Tory gain.
The shock result defied most commentators' predictions, which suggested a hung parliament or slim Tory majority were the most likely outcomes.
Speaking on the BBC, Shadow Chancellor John McDonnell said the result will be "extremely disappointing" if it is "anywhere near this".
He blamed the predominance of Brexit in the election.
When presenter Andrew Neil put it to him the result would mean "it's over for you and Mr Corbyn", Mr McDonnell said: "We'll make the appropriate decisions."
Mr Neil later said he had seen a briefing note circulated to Labour's shadow cabinet which told them to blame the result solely on Brexit.
Jewish Labour Movement chair Mike Katz tweeted that, if the exit poll proves accurate, it would be "devastating, for people everywhere who would normally look to the the party to speak for them but found them wanting."
In a clear suggestion Jeremy Corbyn should resign, he added: "They and many good MPs will carry the can for the multiple failures of the leader and his team".
Labour’s worse result since 1935. If the exit poll bears out, this is devastating, for people everywhere who would normally look to the party to speak for them; but found them wanting. They & many good MPs will carry the can for the multiple failures of the leader & his team.— Mike Katz (@mikekatz) December 12, 2019
Early results were broadly in line with the exit poll - particularly the Conservatives winning Blyth Valley, which Labour had held since its creation in 1950.
There were hints that Mr Corbyn's supporters would seek to try and retain control of the party.
Laura Parker, national coordinator of pro-Corbyn campaign group Momentum, issued a statement: "We will resist Johnson’s attempt to destroy our NHS. We will keep the Labour Party socialist.
"Obviously we need to wait for the full results but it looks like Brexit dominated. It’s unquestionable that Labour’s policies are popular. Every poll shows it, and there is absolutely no appetite to go back to the centrist policies of old.
"But in this election we were squeezed by Brexit and it was the defining issue."
Alastair Campbell, former Labour spin-doctor under Tony Blair, speaking on the BBC called Momentum "delusional".
This is a developing story and will be updated