A shaking Theresa May vowed to fight on today despite Jeremy Corbyn demanding she quit after her election gamble humiliatingly backfired.

As the Tories suffered staggering losses that could strip them of their majority - or worse - the Labour leader ridiculed Mrs May for calling the contest three tears early in a bid to capitalise on sky-high poll ratings.

But an ashen-faced Prime Minister insisted the country needed a "period of stability" and claimed her party was still on track to have the most MPs.

"It is incumbent on us to ensure that we have that," she said.

As polls close, I'd like to say thank you to everyone who has voted for @UKLabour, for a fairer, better Britain, that works #ForTheMany. pic.twitter.com/SgTolSoM00

— Jeremy Corbyn (@jeremycorbyn) June 8, 2017

I love this! @JWRSinclair "if the Conservatives are your taste there are blue raspberry bon bons, if it's Labour, strawberry sherbets" pic.twitter.com/KUrwaDeBNb

— Gia Garrick (@giaisonline) June 9, 2017

Down at Thistle Inn for #GE2017 lunch where @UKinNZ Jonathan Sinclair & Dutch Ambassador @RobZaagman are playing risk... well, the UK is: pic.twitter.com/rHu5pfchl0

— Gia Garrick (@giaisonline) June 8, 2017

In an unbelievable turnaround, the odds on Corbyn becoming the next PM have been slashed, while May is already being savaged by her own party.

Voters appear to be punishing her for calling the ballot unnecessarily and a catastrophic campaign in which she was seen as having performed dreadfully.

In a speech after being re-elected in Islington North, Corbyn said she had wanted a mandate but been given a devastating verdict by voters.

"'That is enough to go, actually, and make way for another government," he demanded.

"Politics is not going back into the box where it was before."

Deputy Labour leader Tom Watson said May would "never recover" and mocked her claim to be a "bloody difficult woman", saying she was now finding it "all too bloody difficult".

Former chancellor George Osborne snarled that the numbers looked 'catastrophic' for the Conservative leader.

Despite Tory hopes they would be the biggest winners from a massive Ukip collapse, the exit poll at 10pm last night indicated they were on track to lose 16 seats, leaving them on 314 and well short of a majority - while Labour was up from 232 to 266.

However, things became even more grim for May, with Education Secretary Justine Greening barely clinging on in Putney and Treasury minister Jane Ellison losing Battersea amid a London meltdown.

Cabinet Office minister Ben Gummer has been defeated in Ipswich, and there has also been a miserable showing in Wales, while Home Secretary Amber Rudd could fall with a recount under way in her Hastings seat.

The only bright spot appears to be Scotland, where they are making gains from the SNP including unseating the party's Westminster leader Angus Robertson in Moray.

The BBC is currently forecasting that the Tories could end up with 322 seats to Labour's 261, just about enough for a workable majority, but many are expecting the final tally to be lower.

Meanwhile, former Lib Dem leader Nick Clegg became the biggest casualty so far as he lost Sheffield Hallam to Labour - but former business secretary Vince Cable fared better as he made a comeback in Twickenham.

A hung parliament could throw Britain into chaos, leaving us effectively rudderless barely a week before negotiations with the EU are due to get under way. Former Ukip leader Nigel Farage said he was ready to return to politics, warning that he feared a second referendum on Brexit.

Senior Conservatives said that May had made "fundamental strategic errors" and said that her closest aides should be "banished" from Downing Street.

They complained that the campaign had been centred around a "cult of personality" and "central control", adding: "It has completely blown up in our face".

One senior Tory told The Telegraph: "This is bad, it's worse than bad. Her advisers should walk out of the door now never to return, regardless of the final result. They should be banished forever.

"Can she hang on? She [Theresa] has zero credibility if this exit poll is correct.

"The very best we can get tonight is to end up where we were."

The survey predicted the Conservatives would get 314 seats and the Labour Party 266.

It projected 34 for the Scottish National Party and 14 for the Liberal Democrats.

The pound lost more than 2 cents against the dollar within seconds of the exit poll announcement, before recovering slightly.Based on interviews with voters leaving polling stations across the country, the poll is conducted for a consortium of UK broadcasters and regarded as a reliable, though not exact, indicator of the likely result.

If confirmed, the result will be humiliating for May, who called a snap election in the hope of increasing her majority and strengthening Britain's hand in exit talks with the European Union.

If she has failed, she could face pressure to resign.

"If the poll is anything like accurate, this is completely catastrophic for the Conservatives and for Theresa May," former Conservative Treasury chief George Osborne told ITV.

"Clearly if she's got a worse result than two years ago and is almost unable to form a government, then she, I doubt, will survive in the long term as Conservative Party leader."

The Labour campaign in Britain's snap general election "has changed politics for the better," Labour leader Jeremy Corbyn says.

"Whatever the final result, our positive campaign has changed politics for the better," Corbyn said in a message via Twitter.

Labour's manifesto had given a "radical vision for a fairer Britain," he said after an exit poll suggested Labour had performed better than expected.

"Our team has worked so hard on this campaign - from door knocking to social media - and it's great that we've won so much support across the country."

A party needs to win 326 seats in the 650-seat House of Commons to form a majority government.

The Conservatives held 330 seats in the last Parliament, compared with 229 for Labour, 54 for the Scottish National Party and nine for the Lib Dems.

During the last election, in 2015, the Conservatives did better than the exit poll predicted, and senior Conservatives said they would take a wait-and-see approach.

"It's still very, very early in the evening," Northern Ireland Secretary James Brokenshire said.

"It's too early in the night to be drawing conclusions".

The forecast is much better than expected for the opposition Labour Party, which had been expected to lose seats.

Labour economy spokesman John McDonnell, one of Corbyn's main lieutenants, urged caution.

"I'm a natural pessimist, and we'll see whether I'm an optimist in the morning," he said.

The result could also be bad news for the Scottish National Party, which is predicted to lose 20 of its 54 seats - though the pollsters cautioned that there is a lot of uncertainty around the Scottish forecast.

A big loss could complicate the SNP's plans to push for a new referendum on Scottish independence as Britain prepares to leave the EU.

Results will come in overnight after an unsettled election held in the shadow of three deadly attacks in as many months.May called the election seven weeks ago - three years ahead of schedule and with her party was well ahead in the polls.

She argued that increasing the Conservative majority in Parliament would strengthen Britain's hand in Brexit talks. But things didn't go to plan.

Brexit failed to emerge as a major issue in the campaign, as both the Conservatives and Labour said they would respect voters' wishes and go through with the divorce.

Then attacks that killed 30 people in Manchester and London twice brought the campaign to a halt, sent a wave of anxiety through Britain and forced May to defend the government's record on fighting terrorism.

Eight people were killed near London Bridge on Saturday when three men drove a van into pedestrians and then stabbed revellers in an area filled with bars and restaurants.

Two weeks earlier, a suicide bomber killed 22 people as they were leaving a concert in Manchester.

Before the election, five people died during a vehicle and knife attack near Parliament on March 22.

Rachel Sheard, who cast her vote near the site of the London Bridge attack, said the election hadn't gone as expected - and that it certainly wasn't about Brexit.

"I don't think that's in the hearts and minds of Londoners at the minute, (not) nearly as much as security is," said Sheard, 22.

"It was very scary on Saturday."

May, who went into the election with a reputation for quiet competence, was criticized for a lacklustre campaigning style and for a plan to force elderly people to pay more for their care, a proposal her opponents dubbed the "dementia tax."

As the polls suggested a tightening race, pollsters spoke less often of a landslide and raised the possibility that May's majority would be eroded.

In her final message to voters, May tried to put the focus back on Brexit.

"I can only build that better country and get the right deal in Brussels with the support of the British people," she said.

"So whoever you have voted for in the past, if that is the future you want then vote Conservative today and we can all go forward together."

Corbyn, an old school left-winger widely written off at the start of the campaign, has drawn thousands of people to upbeat rallies and energised young voters with his plans to boost spending on health and education after years of Conservative austerity.

Corbyn told supporters at his final rally that Labour's campaign had "changed the debate and given people hope. Hope that it doesn't have to be like this; that inequality can be tackled; that austerity can be ended; that you can stand up to the elites and the cynics. This is the new center ground."

Security dominated the late stages of the campaign, after the attacks in Manchester and London. May said this week that she would consider rewriting human rights legislation if it gets in the way of tackling extremism.