UK Independent Party (UKIP) leader Nigel Farage addresses the media in central London on May 3, 2013. The anti-immigration party was celebrating some of its best ever results following local elections which delivered a bloody nose to Britain's ruling coalition. (BEN STANSALL/AFP/GETTY IMAGES)

The Conservative-led coalition of Prime Minister David Cameron just got served.

The anti-immigration U.K. Independence Party staged a dramatic surge Thursday in local elections in England and Wales, with results on Friday showing voters delivering a brutal whipping to the Conservatives and their junior coalition partners, the Liberal Democrats.

Political pundits said the results represented one of the strongest showings by a non­traditional party in Britain since World War II, with the gains underscoring the rise of populist and nationalist parties across Europe.

At the core of the party’s platform are aspirations to withdraw Britain from the European Union and impose new curbs on immigration, and the powerful showing sets U.K. Independence up to be an increasingly influential force in British politics. In recent months, its growing support in national polls had already sparked Britain’s three major parties — the Conservatives, Labor and the Liberal Democrats — to float increasingly strict proposals aimed at stemming the tide of foreigners.

Cameron, for instance, has pledged to hold a national referendum on Britain’s membership in the E.U. by 2017. Observers predicted that Cameron could face pressure to move up that timetable in response to U.K. Independence’s surge.

On national television Friday, the party’s jubilant leader, Nigel Farage, grinned for the cameras and offered cheery thumbs-up signs, a sharp contrast to the dour faces of Conservatives and Liberal Democrats, who squirmed as reporters pelted them with questions about how and why they could have lost so many seats in counties across England and Wales.

“We have been abused by everybody, the entire establishment, and now they are shocked and stunned that we are getting over 25 percent of the vote everywhere we stand across the country,” Farage told the BBC. “This is a real sea change in British politics.”

The performance by a party Cameron once described as being filled with “fruitcakes, loonies and closet racists” raised the question of whether its gains amounted to a temporary protest vote or signaled the birth of a more powerful political movement. Farage, like Beppe Grillo — a comedian whose Five Star Movement took Italy by storm in elections in February — has used a mix of humor and charm to sell voters on a populist and anti-establishment message. It is a message that British voters appear to be responding to as never before.

“This is a jolt against the entire political establishment,” said Tony Travers, a political analyst at the London School of Economics. “What we don’t know is whether they will disappear like snow in hot weather by the next elections or whether they become an important force.”

Formed in 1993 by factions on the political right opposed to Britain’s membership in the E.U., U.K. Independence has yet to win a seat in the national Parliament. But it is coming closer. On Thursday, the party staged its second strong finish this year in a special election for a national seat, narrowly losing to a Labor candidate and pushing the Conservatives to third.

In local elections, the Conservatives lost 335 seats while the Liberal Democrats shed 124. U.K. Independence, meanwhile, picked up 139 seats.

The Labor Party — the chief opposition in Britain — gained 291 seats. But Farage’s party had run in fewer races and got by with a fraction of the support staff of its rivals.

In fact, analysts said Labor’s failure to pick up even more seats despite Britain’s prolonged economic malaise suggested that its leader, Ed Miliband, had thus far failed to put the party on a clear victory footing ahead of the 2015 general elections. It also suggested that rather than moving to the political left, a significant portion of Britons unhappy with the current Conservative-led government was instead shifting further to the right.

All of the traditional parties were racing Friday to offer mea culpas to the electorate.

“It is a challenge to us, it’s a wake-up call for us to actually listen to people who feel that times are hard and wonder whether any of us have actually got the answers,” Harriet Harman, deputy head of the Labor Party, told the BBC.

Although Labor and the Liberal Democrats also lost seats to U.K. Independence, the Conservatives suffered the worst. And on Friday, Cameron was backing away from his old characterizations of the party’s supporters as a lunatic fringe.

“Look, I understand why some people who’ve supported us before didn’t support us again. They want us to do even more, to work for hard-working people, to sort out the issues they care about, more to help with the cost of living, more to turn the economy around, more to get immigration down, to sort out the welfare system,” Cameron told the BBC. “They will be our focus, they are our focus, but we have got to do more.”

Eliza Mackintosh contributed to this report.