Britain’s Conservatives have lost their majority in a snap general that has resulted in a hung parliament.
With just a handful of seats left to declare, Thursday’s poll shows gains for the opposition Labour Party.
This is seen as a humiliation for PM Minister Theresa May, who chose to call the election to try to strengthen her hand in talks with the EU on Brexit.
Labour leader Jeremy Corbyn urged her to resign, but she said her party would “ensure” stability in the UK.
“At this time more than anything else, this country needs a period of stability,” Mrs May said.
“And if, as the indications have shown and if this is correct that the Conservative Party has won the most seats and probably the most votes, then it will be incumbent on us to ensure we have that period of stability – and that is exactly what we will do.”
But EU Budget Commissioner Günther Oettinger told German radio he was unsure Brexit talks could start later this month as scheduled. He said discussions with a weak UK negotiating partner could lead to a poor outcome.
Mr Corbyn earlier said: “If there is a message from tonight’s results, it’s this: the prime minister called this election because she wanted a mandate. Well, the mandate she’s got is lost Conservative seats, lost votes, lost support and lost confidence.”
“I would have thought that’s enough to go, and make way for a government that will be truly representative of all of the people of this country,” he added.
The pound earlier fell sharply in value after the BBC/ITV/Sky Exit poll was published when the voting ended at 22:00 BST (21:00 GMT).
Final election results are expected by Friday lunchtime.
The biggest shock of the night so far has been the Liberal Democrat MP Nick Clegg losing his seat to a Labour candidate. He was deputy prime minister of the UK from 2010 to 2015 in a coalition government with the Conservatives.
Former Scottish National Party leader Alex Salmond was also defeated, losing his seat to a Conservative.
A total of 650 Westminster MPs are being elected, with about 45.8 million people entitled to vote. A party needs 326 seats to have an overall majority.
Prime Minister Theresa May – who had a small majority in the previous parliament – called an early election to try to improve her negotiation positions on Brexit.
But analysts say it is clear the PM made a serious miscalculation.
The BBC’s political editor Laura Kuenssberg says Mrs May’s decision may prove to have been one of the biggest political mistakes of modern times.
