May, who became prime minister after the June 2016 referendum on leaving the European Union, had called the election three years early in a bid to strengthen her hand in the looming Brexit negotiations.
Scottish Conservative leader Ruth Davidson, who took the party from one Scottish seat to 13, said there would now have to be "consensus within the country about what it means and what we seek to achieve as we leave".
May will also need the support of the socially conservative, pro-Brexit Democratic Unionist Party (DUP) which won 10 seats in Northern Ireland. The Conservatives were rejected in England and the ruling Scottish National Party lost 21 seats in Scotland, where a second independence vote is now highly unlikely. Weeks later, of course helped by the chaotic Tory campaign, brand Corbyn nearly achieved the impossible - closed the gap in the polls and came to be viewed as humble, human and in touch.
With 649 of 650 seats declared, the Conservatives had won 318 seats.
"The British need to negotiate their exit but with a weak negotiating partner, there is a danger that the talks are bad for both parties", he told German radio.
"The mandate she has got is lost Conservative seats, lost votes, lost support and lost confidence", he said.
May's chief of staff Nick Timothy, left, and Joint-chief of staff Fiona Hill leave the Conservative Party headquarter on Friday. They prefer a hung parliament instead of giving a clear majority to Conservatives. "That's not a matter for me", she said. But like the Brexiteers, Trump and Bernie Sanders before him, Corbyn wasn't playing within the existing political frame; he was seeking to break it. There's the "hard Brexit" and the "soft Brexit". "Her advisers should walk out of the door now never to return, regardless of the final result".
"To their critics they're a bunch of authoritarian, illiberal bible-bashers who are deeply sectarian and not the kind of party that anybody in Britain would ideally want holding the government, as it were, to ransom". He is facing the Conservatives, the right-wing media and the British establishment on the one hand and his party's right-wing pro-capitalist rebels on the other.
It was a painful reckoning for a prime minister whose election gamble failed in a stunning fashion.
"I am delighted to see Labour do so well", the Vermont senator said in a Facebook post, linking to a Guardian news story. A buoyant Corbyn piled on pressure for May to resign, saying people have had enough of austerity politics and cuts in public spending.
If a party has 326 MPs or more it will be able to form a majority government and secure sufficient backing to ensure it can pass legislation.
Mrs May had unexpectedly called the snap election seven weeks ago, even though no vote was due until 2020. Until yesterday, Theresa May campaigned. "They didn't want to leave the EU".
Page said Corbyn, a lifelong left-wing activist who has spent decades speaking to crowds, was underestimated as a campaigner. "This is still on", Corbyn told the Sunday Mirror newspaper.
Mr Corbyn's closest ally, the Shadow Chancellor John McDonnell, said: "We have laid the foundations for a minority government, and then eventually a majority government".
But the firestorm of criticism continued unabated early Saturday after May announced she would keep her ministerial team unchanged and planned to stay in power with the aid of a small Northern Irish party. Mrs May's shock policy on social care upset the elderly voters the Conservatives rely on and derailed her bid for election. They sent a wave of anxiety through Britain and forced May to defend the government's record on fighting terrorism.
From the parties' inability to work together, to fears of another election or even a bad Brexit deal, voters want to know what the future holds and what sort of government the United Kingdom will get in the end.
Just as most of those supposedly in the know said Britons would never vote to leave the European Union or that Donald Trump would never be the Republican nominee for president, never mind occupy the White House, critics both within and without Labour claimed that Corbyn, a rumpled, unabashed socialist with a deficit of traditional charisma, was sure to run his party into the ground.