Britain's Prime Minister Theresa May arrives with her husband Philip for the declaration in the general election at her constituency in Maidenhead, England, Friday, June 9, 2017. British Prime Minister Theresa May's gamble in calling an early election appeared Friday to have backfired spectacularly, after an exit poll suggested her Conservative Party could lose its majority in Parliament. (AP Photo/Alastair Grant)
Britain's Prime Minister Theresa May arrives with her husband Philip for the declaration in the general election at her constituency in Maidenhead, England, Friday, June 9, 2017. British Prime Minister Theresa May's gamble in calling an early election appeared Friday to have backfired spectacularly, after an exit poll suggested her Conservative Party could lose its majority in Parliament. (AP Photo/Alastair Grant) Credit: Alastair Grant

London — British Prime Minister Theresa May’s decision to call an early election in a bid to strengthen her grip on power appeared early this morning to have spectacularly backfired, with her Conservative Party at risk of losing its parliamentary majority, according to exit polls and partial official results.

The outcome — an astonishing turn following a campaign that began with predictions that May would win in a historic landslide — immediately raised questions about whether she could maintain her hold on Downing Street. It also threw into doubt the country’s plans for leaving the European Union.

As of 3 a.m., a projection based on a combination of exit polls and official results put the Conservatives at 322 seats — four short of what they would need for a working majority in the 650 member Parliament and down from the 331 they won just two years ago.

The Labour Party was forecast to win 261 seats — an unexpected gain of dozens of seats under far-left leader Jeremy Corbyn. The outcome gave him at least a chance, albeit a remote one, of becoming prime minister — something virtually no one had thought possible before Thursday’s vote.

The results, if they hold, would mark the second time in as many years that the British people have defied predictions, scrambled the country’s direction and bucked the will of a prime minister who had gambled by calling a vote when none had not been required.

But unlike last year’s EU referendum — which delivered a clear if close verdict to get out of the bloc — the will of the voters who cast ballots on Thursday was not nearly as easy to decipher.

There was little doubt that the Conservatives would emerge, once again, as the largest party. But as Labour unexpectedly picked off seats — especially in areas of London that had voted last year to remain in the EU — May’s once-undisputed political authority, and even her ability to continue as prime minister, were being called into question.

“The prime minister called this election because she wanted a mandate,” said Corbyn in a speech after winning reelection to his north London seat. “The mandate she’s got is lost votes, lost Conservatives seats, lost confidence.”

Corbyn then said May should resign.

Minutes later, a nervous-sounding May delivered her own speech in which she said that as long as the Conservatives remain the largest party, they should be allowed to govern. “The country needs a period of stability,” she said.

The results raise questions about whether either major party will have enough support to form a government without resorting to forming a coalition — a scenario known as a hung parliament.

If it comes to that, it’s far from clear which parties would team up, or under what arrangements. A “progressive alliance” — including Labour, the Liberal Democrats, Scottish and Welsh nationalists, and others — may have as many seats as the Conservatives. But the Conservatives would also have potential coalition partners if they fall short of a majority, including unionists in Northern Ireland.

In the early minutes after the exit polls’ release, the pound fell 2 percent as investors reacted to potential political turmoil. Sterling dropped to 1.2750 against the U.S. dollar, its lowest level since May’s call for a snap election in April.

Tories were incredulous as the exit poll numbers emerged, saying that they thought the results had undersold the party’s performance and that official tallies would give them a higher total.

But as the results rolled in, they grew more somber and acknowledged suffering losses.

In Europe, observers were bracing for more instability out of Britain.

“Could be messy for the United Kingdom in the years ahead,” tweeted former Swedish prime minister Carl Bildt. “One mess risks following another. Price to be paid for lack of true leadership.”

May had acknowledged that a result such as the one signaled in the exit polls would be a defeat.

“If I lose just six seats I will lose this election, and Jeremy Corbyn will be sitting down to negotiate with the presidents, prime ministers and chancellors of Europe,” she wrote on her Facebook page last month.

Although exit polls have been imprecise in past elections, they are seen as a fairly reliable guide to the overall results. Official tallies will stream in through the night in Britain, with the final outcome not known until this morning.

The exit poll results, if accurate, will draw renewed scrutiny to May’s choice to gamble by going back on repeated promises not to call an election before the one that had been due in 2020. They could also leave Britain rudderless just as what are sure to be contentious talks are scheduled to get underway with European leaders over the terms of Brexit.

May in April broke her vows not to call a snap vote, telling the country that she needed a stronger mandate before she began Brexit talks.

Corbyn spent little time during the campaign discussing Brexit. Like May, he favored “remain” during the referendum. But also like May, he has promised not to obstruct the will of voters and to follow through on their desires for an exit if he is elected.

The election follows a turbulent campaign that was interrupted by two mass-casualty terrorist attacks, and that had been marked by a faltering performance by May even as Corbyn exceeded expectations.

Despite security concerns, the election unfolded peacefully from the remote Scottish isles to the bustling lanes of London, with Britons using stubby pencils to mark their ballots at schools, church halls, pubs, railway cars and other voting sites nationwide.

When May called the vote, observers hailed the move as a cunning bit of political strategy and predicted she would win in a landslide that could deliver her the sort of overwhelming parliamentary majority that predecessors Margaret Thatcher and Tony Blair had enjoyed.

May came to power last year, emerging to claim the nation’s top job following the political wreckage of the country’s astonishing choice to leave the European Union.

Since then she has had only a slender majority in Parliament — won in a 2015 election when the country was governed by her predecessor, David Cameron — and she had feared that without a bigger cushion she would lack the latitude she needs for Brexit talks.

Early pre-election polls suggested that she would get what she wanted, with the Conservatives enjoying leads of 20 points or more over the far-left Corbyn and his Labour Party.

But May, who endlessly touted herself as a “strong and stable” leader on the campaign trail, finished the race being tagged by critics as “weak and wobbly” after high-profile U-turns and a generally underwhelming delivery as a retail politician.

In the final days of campaigning, polls showed the Conservative lead withering to as little as a single point.

“We’ve learned what we suspected all along: She’s not particularly fast on her feet, she’s not a natural campaigner, she’s not really a people person,” said Tim Bale, a politics professor at Queen Mary University of London.

Lacking the common touch, May’s strategy was to focus the campaign on a presidential-style choice between her leadership skills and those of Corbyn. She relentlessly hammered her rival as a far-left throwback to another era who would leave the country vulnerable in both the Brexit talks and at a time of growing terrorist threats.

Corbyn — for decades a far-left backbencher who unexpectedly vaulted to the party’s leadership in 2015 — faced a steeply uphill challenge to sell himself as a potential prime minister.

But he was widely seen to have mounted a far more credible challenge than many thought possible, running a nothing-to-lose campaign focused on ending seven years of Tory austerity and shrinking the gap between rich and poor.

Even if he doesn’t prevail, his performance may have helped his chances of hanging on as Labour leader — a stinging blow for more-centrist party figures who had quietly hoped the harsh glare of a national campaign would leave him exposed and force him to step aside.