David Cameron's Conservatives win majority in British general election

British Prime Minister David Cameron's Conservative party on Friday won a majority in the House of Commons in the general election, results showed.

With seven seats still to declare, the Tories secured the 326 required for a majority in the 650-seat chamber, allowing the party to form a government without the need for a coalition.

The victory reportedly comes as a surprise and could redefine the country's future in Europe and herald more austerity cuts.

"This is clearly a very strong night for the Conservative party," Cameron said after being re-elected to his Witney seat in southern England.

Cameron stressed that Britain now "must hold" a referendum on membership of the European Union that he has promised by 2017.

Ed Miliband has resigned as the leader of the Labour party and admitted it had been "a very disappointing and difficult night".

He will remain in parliament.

"We haven't made the gains we wanted in England and Wales, and in Scotland we have seen a surge of nationalism overwhelm our party," he said.

As well as the Conservatives, the other big winners were the pro-independence Scottish National Party (SNP), which has so far won 55 of the 59 seats north of the border, up from just six seats that it held before Friday's election.

Its winners included 20-year-old Mhairi Black, Britain's youngest MP since 1667, who defeated Labour's campaign chief Douglas Alexander.

But it was a terrible night for the Liberal Democrats, junior partners in Cameron's coalition since 2010, who lost at least two senior ministers.

Their leader, deputy prime minister Nick Clegg, said the centrists had suffered a "cruel and punishing" night and hinted he could step down.

The success of the SNP could increase pressure for a fresh referendum on Scottish independence, even though that was rejected just last September.

"I voted for the Conservatives because Labour is not competent on financial matters," said Ben Woodthorpe, 39, as he sipped a beer in a pub in the City of London financial district.

The mood in the Labour camp was, by contrast, glum.

"I am very disappointed because it looks like the majority is going towards the Conservative side," said Nick Mabey, a Labour supporter in London.

"Labour has been screwed by what happened in Scotland," he said.

The pound rose to $1.5479 in Asian trading, its highest level since late February.

"The Conservative Party are perceived to be more market-friendly than a Labour government and that's really at the core of the game," said Sebastien Galy, a currency strategist at Societe Generale bank.

Cameron would extend an austerity drive borne out of the 2008 global financial crisis, with the Conservatives vowing to bring the budget of the world's fifth-biggest economy back to balance.

As the SNP turned the electoral map of Scotland yellow, its former leader Alex Salmond, who was replaced by Nicola Sturgeon last year, was among the lawmakers returned to the House of Commons.

He summed up the sense of euphoria in the pro-independence party in which he is still a figurehead, saying the "Scottish lion has roared".

"There is a roch (rough) wind blowing through the great glen of Scotland this morning," he said.

"There is a swing underway in Scotland the like of which has not been seen in recorded politics."

Under Britain's electoral system, a party needs to be able to command a majority in the 650-seat House of Commons in order to form a government.

While Cameron may fall just short of that figure, British newspaper front pages reflected expectations that he will return to 10 Downing Street.

"Swinging the blues" was the front page of Conservative-supporting Sun, referring to the Conservative party colours.

But the front page of the left-leaning Daily Mirror was black except for the words "General Election 2015. Condemned Again... Five more damned years?"