Labour is forecast to have a 170-seat majority in the Commons, with the Conservatives reduced to their lowest number of MPs on record.
If the results indicated by an exit poll are accurate, Rishi Sunak's term as Prime Minister will end in electoral disaster, with Nigel Farage's Reform UK establishing a foothold in Parliament and the Liberal Democrats forecast to make significant gains.
Shadow education secretary Bridget Phillipson held Houghton and Sunderland South for Labour in the first confirmed result of the night, but Reform pushed the Conservatives in an early indication of the advances made by Farage's party.
"Tonight the British people have spoken and if the exit poll this evening is again a guide to results across our country - as it so often is - then after 14 years the British people have chosen change", Phillipson said.
"They have chosen Labour and they have chosen the leadership of Keir Starmer. Today our country with its proud history has chosen a brighter future."
Early results in the UK election are bearing out predictions of a Labour triumph. (EPA PHOTO)
The exit poll suggests Labour is on course for 410 seats, with the Tories reduced to 131.
The Liberal Democrats are forecast to win 61 seats, Reform UK on 13 and the Green Party two.
In Scotland, the SNP are expected to secure 10 seats with Plaid Cymru in Wales on four.
The poll for broadcasters involved more than 20,000 voters at 133 polling stations.
If the results follow the forecast, it will mean a Labour prime minister in No 10 for the first time since 2010 and the Conservatives facing a fight for the future direction of the party.
Former justice secretary Sir Robert Buckland was the first high-profile Tory casualty as he lost to Labour in Swindon South.
He warned that a lurch to the right after the election would be "disastrous" for the Conservatives and took aim at "ill-discipline" within the Conservative Party after losing his seat.
Former Cabinet minister Sir Jacob Rees-Mogg said it is "clearly a terrible night", suggesting voters had been put off by the revolving door in No 10 which saw Boris Johnson replaced first by Liz Truss and then by Mr Sunak.
"Voters expect the prime minister they have chosen to remain the prime minister and for it to be the voters who decide when that person is changed", Rees-Mogg told the BBC.
After 14 years in power, it was always going to be a difficult election for the Conservatives, but the sometimes shambolic campaign - triggered at a time of Mr Sunak's choosing - has contributed to the party's likely defeat.
From the rain-drenched speech announcing the surprise July 4 poll, through to the D-Day debacle as he left Normandy early to record a TV interview, Mr Sunak struggled to convince the electorate he was the right man to lead the country.
The Prime Minister was not helped by the scandal of Tory candidates and officials allegedly heading to the bookies armed with inside knowledge of the date.
Mr Sunak is expected to resign after leading his party to a massive defeat, but many of the contenders jostling to replace him are nervously awaiting their own constituency results to see if their leadership dreams survive the night.
The likes of Penny Mordaunt, Grant Shapps and Steve Baker all face battles to return to Parliament, while Chancellor Jeremy Hunt is predicted to lose.
Meanwhile, Nigel Farage said Reform would win "many, many seats" across the country.
He added: "This is going to be six million votes plus. This, folks, is huge."
Lib Dem leader Sir Ed Davey said his party was "on course for our best results in a century".
with Reuters
