If the results are confirmed, it will be a huge embarrassment for May, who in April called a snap election three years ahead of schedule in the hope of gaining an even greater majority of seats to give her a stronger mandate for upcoming Brexit negotiations. Those negotiations could now take on a very different approach.
The poll, compiled for the UK’s main television broadcasters, suggests the Conservatives will be the largest party but will secure only 314 of the 650 seats in Parliament’s House of Commons — a loss of 17 seats. The main opposition Labour Party is tipped to win 266 seats, a gain of 34.
If no party has 326 seats and an overall majority, it’s called a hung Parliament — that result could plunge the country into political uncertainty, as the Conservatives are likely to try to form a coalition. But several parties have already said they will not work with the Conservatives, including the the Liberal Democrats, who are projected to win 14 seats.
Labour could also try to form a coalition and propel their leader, Jeremy Corbyn, to the country’s leadership, but as the numbers stand, Labour would struggle to garner enough seats.
The exit-poll scenario is the latest jolt in the world of British politics. It’s been a tumultuous 12 months since the country voted to leave the European Union in the Brexit referendum last year, against projections.
Brexit talks could derail
May had promised a “hard Brexit” if Britain did not like the terms of the divorce negotiated with the EU. She vowed to take the country out of the EU’s single market and customs union, essentially a free-trade zone, radically changing Britain’s relationship with one of its biggest trading partners.
The value of the British pound tumbled 1.6%, to $1.27, immediately after the exit poll results came out.
Some observers are looking at the poll results as the public’s rejection of May’s Brexit plan.
The polls also suggest that, as with Brexit, opinion polls ahead of the vote were off base.
Marcus Roberts, a pollster for YouGov told CNN the results were “extraordinary” as they had been predicting a Conservative landslide.
“It will be seen as a triumph for Jeremy Corbyn,” Roberts said.
A number of polls gave May and her party a 20-point lead when she called the election.
History Professor Margaret MacMillan from Oxford University said: “If the numbers stay as they are, it’s probably going to be the end of Theresa May as leader of the Conservative Party.”
What official results show so far
Exit polls in Britain are not official results, but they have been accurate in the past.
Individual results are now being declared and the full outcome should become clear in a few hours.
Rutherglen and Hamilton West in Scotland was the first constituency to change hands, official results show. The Scottish National Party lost the seat to Labour.
May’s Conservatives scored one early victory, however, retaining its seat in the bellwether seat of Nuneaton in central England.
“This suggests the Conservatives could be doing marginally better than expected from the exit poll,” writes journalist Jane Merrick for CNN.
“But, in a sign that a Conservative landslide is a distant prospect, Labour held onto Darlington, a seat in northeast England that May had hoped to win if she were on course for a convincing majority,” she added.
May experienced a gradual slide during the campaign period, in which a wide gap between the Conservatives and Labour narrowed.
Predictions of Conservative success became more modest as the party’s campaign faltered following a series of missteps.
May was criticized for making a number of U-turns on social welfare and she came under fire for a controversial proposal on who should pay for the cost of care for the elderly, a policy that became known as the “dementia tax.”
Her opponents also took issue with her refusal to take part in a televised debate with other party leaders.
The Prime Minister called what she thought would be a Brexit-focused election, but the issue was quickly overshadowed by security as two deadly terror attacks, in Manchester and London, struck during the campaign period.
The attacks only put May under more scrutiny for national security decisions she made during her tenure as Home Secretary, a role she held for six years in the government of her predecessor, David Cameron.
The attacks triggered a heated debate on whether the police are well-enough resourced to deal with terror threats. Police numbers across the UK were cut by 20,000 under May’s watch as Home Secretary.
The exit polls also mark an unexpected rise for Corbyn, who has hung on as Labour leader through several attempts from senior members of his party to oust him.
“If this result plays out, Corbyn has defied all expectations and denied Theresa May a majority. It would be a major endorsement for his brand of left-wing populist politics as well as for him personally,” journalist Merrick says.
CNN’s Carol Jordan, Richard A. Greene, Melissa Mahtani and Bryony Jones contributed to this report.
By Angela Dewan and James Masters, CNN