Britain's Prime Minister David Cameron and his wife Samantha wave as they arrive at Number 10 Downing Street in London, Britain May 8, 2015.[Photo/Agencies]

LONDON - British Prime Minister David Cameron won an emphatic election victory in Britain, overturning predictions that the vote would be the closest in decades to sweep into office for another five years, with his Labour opponents in tatters.

The sterling currency and share prices soared on a result that reversed expectations of an inconclusive "hung parliament" with Cameron jockeying for power with Labour rival Ed Miliband. Instead, Cameron was due to meet Queen Elizabeth before noon to accept a swift mandate to form a government.

But despite the unexpectedly decisive outcome, more uncertainty looms over whether Britain will stay in the European Union - and even hold together as a country.

Scottish nationalists swept aside Labour, meaning that Scotland, which voted just a year ago to stay in the United Kingdom, will send just three representatives of major British parties to parliament and be all but shut out of the cabinet. That could revive calls for it to leave Britain.

Cameron's victory also means Britain will face a vote which he has promised on continued membership in the EU. He says he wants to stay in the bloc, but only if he secures changes to its rules in negotiations that have not yet begun.

Cameron returned, smiling, to the prime minister's office in Downing Street early on Friday.

With a few dozen seats yet to be declared in the 650-seat house, the Conservatives were on course for an overall majority to govern alone for the first time since 1992. They could also ask a small party to join them in government if they fall a few seats short.