London, UK: A defiant Prime Minister Theresa May vowed Friday to form a government to lead Britain out of the EU despite losing her majority in a snap general election and facing calls to resign.

"What the country needs more than ever is certainty," the Conservative leader said after the shock outcome of Thursday's vote.

May had called the election three years early in a bid to strengthen her hand in looming Brexit negotiations, but her gamble backfired spectacularly. 

With all but one of 650 seats declared, the centre-right party had the most votes and the most seats but lost its majority in the House of Commons.

Sterling plunged against the dollar and the euro as the election result created even more uncertainty over the whole Brexit process.

May sought permission Friday from head of state Queen Elizabeth II to form a minority government, supported by Northern Ireland's Democratic Unionist Party (DUP).

In a statement outside Downing Street, the 60-year-old premier promised to "fulfil the promise of Brexit".

"It is clear that only the Conservative and Unionist Party has the legitimacy and ability to provide that," she said.

"This will allow us to come together as a country and channel our energies towards a successful Brexit deal."

European Council President Donald Tusk warned there was "no time to lose" in starting the negotiations, with the two-year countdown to Britain's exit from the European bloc already well underway.

- Avoid a 'no deal' -

The Conservatives and the DUP, a socially conservative party that backed Brexit, are expected to work together on a vote-by-vote basis rather than enter a formal alliance.

May confirmed she intended to start talks with the Europeans on June 19 as planned, promising to "get to work".

She later announced that her top ministers, including finance minister Philip Hammond, foreign minister Boris Johnson and Brexit minister David Davis, would remain in their positions.

European Commission chief Jean-Claude Juncker said he hoped there would not be "further delay" in the Brexit talks that "we are desperately waiting for".

Tusk added on Twitter: "We don't know when Brexit talks start. We know when they must end. Do your best to avoid a 'no deal' as result of 'no negotiations'."

May had threatened to walk away from the talks rather than accept a "bad deal", with Britain's exit bill and the fate of EU citizens in Britain among the early obstacles.

But EU budget commissioner Guenther Oettinger said May was now likely to be a "weak" partner.

"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.

- 'Lost confidence' -

The election campaign was rocked by two terror attacks, which drew attention to May's record in her former job as interior minister, while her own performances were heavily criticised.

The vicar's daughter presented herself as a "strong and stable leader" but is now facing calls to resign after throwing away her party's 17-seat majority.

Labour leader Jeremy Corbyn, whose energetic campaign defied predictions of a crushing defeat, told May to quit, saying she had "lost votes, lost support and lost confidence".

May said she was sorry for Conservative members who lost their seats, saying: "I will reflect on what we need to do for the future to take the party forward."

Many in the party believe she has been fatally wounded.

Conservative lawmaker Heidi Allen said Britain needed a prime minister right now so May should stay on, but added that her days were numbered.

"I don’t believe personally that Theresa May will remain as our prime minister indefinitely. In my view it may well just be a period of transition," she told LBC radio.

Former Conservative minister Anna Soubry added that the premier "is in a very difficult place... she now has to obviously consider her position".

With all but one constituency declared, the Conservatives won 318 seats -- down from 331 at the 2015 election -- while Labour was on 261, up from 229.

"Mayhem" screamed the headline on the front page of The Sun, Britain's biggest selling newspaper that is normally sympathetic to the Conservatives.

"Britain is about to find out the price of that failure. Brussels will be licking its lips," it said.

The London Evening Standard, edited by former finance minister George Osborne who May sacked, splashed with a photo of her under the headline "Queen of Denial".

- 'Reckless' hard Brexit -

In a night that redrew the political landscape once again, the UK Independence Party (UKIP) lost millions of voters, triggering the resignation of its leader Paul Nuttall.

The Scottish National Party of First Minister Nicola Sturgeon, which has dominated politics north of the border for a decade, and called for a new independence vote after Brexit, lost 21 of the 56 seats it won in 2015.

Sturgeon said the results showed that "the reckless Tory pursuit of a 'hard Brexit' must now be abandoned."

May, who took over after the June 2016 Brexit referendum, began the formal two-year process of leaving the EU on March 29, promising to take Britain out of the single market and cut immigration.

Despite campaigning against Brexit, Labour has accepted the result but said it would prioritise maintaining close economic ties with the EU.