However, she unpredictably called for early elections in April as she was nearly positive that her part would win the vast majority.
Labour leader Jeremy Corbyn, an old school left-winger widely written off at the start of the campaign, has drawn thousands of people to upbeat rallies and energized young voters with his plans to boost public spending after years of Conservative austerity.
Visibly tired from the night's events, the Prime Minister said she would take time to reflect on how the Conservatives can "take the party forward" from now on.
"She said, 'Give me a mandate.' And the answer was, 'No.' And that means we have to rethink everything, the entirety of the way we're doing Brexit", Dunt said.
Late in the campaign, Britain was hit by two Islamist militant attacks that killed 30 people in Manchester and London, temporarily shifting the focus onto security issues.
When May called the election in April, she did so with the Conservatives riding high in the polls, and the pound had surged on expectations that a big majority for the Conservatives would allow her to face down the so-called euroskeptics in her parliamentary ranks.
With 649 of 650 seats in the House of Commons declared, the Conservatives had 318 to the Labour Party's 261. The rival Labour Party is predicted to get 266 seats, followed by the Scottish National Party with 34 and the Liberal Democrats with 14 seats.
She and her team are trying to produce a small working majority in coalition with the Democratic Unionist Party. "Politicians must act responsibly, putting the interests of the country first and showing the world that the United Kingdom remains a safe destination for business".
The election results create uncertainty surrounding the negotiations over Britain's exit from the European Union.
Who will be prime minister?
The move has been slammed as a "coalition of chaos" by Lib Dem leader Tim Farron, who condemned Mrs May for putting her "party before her country".
But Corbyn, who won his north London seat, said that Labour would work to build a Britain that "works for the many, not the few". "Regardless of the question of who will form a government in Britain, time is ticking". Some colleagues may be lining up to replace her, although a party source told Reuters the post was seen as too much of a poisoned chalice for the time being.
The EU wants a "legally smooth British departure" in March 2019, the wire service says. Minority governments like these are not as secure, as the party with more seats is dependent on the voting support of the less powerful party. U.K. Independence Party said "Theresa May has put Brexit in jeopardy".
Labour voters were more likely to be concerned about the NHS and spending cuts - only eight per cent said Brexit was the most important factor in their vote.
'I'm very happy about that.
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