Nick Clegg, Britain's deputy prime minister and leader of the Liberal Democrat party, holds a leaflet during a debate on Britain’s future in the E.U. with UK Independence Party leader Nigel Farage. (Handout/Reuters)

For years, Nigel Farage has operated on the fringes of British politics, dismissed as a demagogue — or worse — for his strident calls to get out of the European Union and dramatically limit immigration.

But with a little more than a month to go before European parliamentary elections, the U.K. Independence Party leader is rapidly becoming the man of the moment in British political life.

The most vivid sign of Farage’s transformation came Wednesday night, when he debated Deputy Prime Minister Nick Clegg in prime time over Britain’s ever-conflicted relationship with the E.U. After an hour of vigorous jousting, Farage ended with a characteristic flourish, calling on Britons to “join the people’s army and topple the establishment that got us into this mess.”

Minutes later, poll results suggested that the public may be ready to take up his challenge, with surveys of those who had tuned in showing that the freewheeling Farage had crushed the sober and centrist Clegg by a margin of more than 2 to 1. Polls taken after a debate last week also showed a wide margin for Farage.

The results reflect the broader rise of Farage — and UKIP — as British voters look for alternatives beyond the three major parties that have dominated the country’s politics for decades. They also mirror the growth of right-wing sentiment across Europe. In local French elections Sunday, the far-right National Front won some of the biggest victories in the party’s history, capturing control of towns nationwide.

Farage has rejected comparisons to the National Front and other far-right groups in Europe, vowing that UKIP won’t engage the overt racial focus targeting Jews, Muslims and others that has helped the far-right groups gain votes.

But UKIP plays on some of the same grievances, and Farage has spoken derisively of a Britain that has been rendered “unrecognizable” by mass immigration over the past decade.

On Wednesday, he said Britain’s open borders with the rest of the E.U. had “left a white working class effectively as an underclass. And that, I think, is a disaster for our society.”

Research shows that UKIP supporters tend to be whiter, poorer and less educated than the national average. Farage, a former commodities trader who worked for two decades in London’s financial sector before turning to politics, has proved skillful at channeling the anger of those Britons who suffered through a prolonged economic downturn and now are seeing few benefits even as growth picks up.

“It’s always easier to blame your woes on one cause, and preferably one person,” said Rodney Barker, a political analyst at the London School of Economics. “What Nigel Farage has done is convince people that everything is the fault of Europe.”

UKIP has been around since 1993 and has long railed against the tyranny of Brussels, headquarters of the E.U. But it is only in recent years that the party has gained real traction.

A poll released Thursday by the research firm YouGov shows that it is on pace to take 13 percent of the vote in the general election, putting it ahead of Clegg’s Liberal Democrats for third place. Labor is slightly ahead of the Conservatives in the race for first.

But the general election is still more than a year away, and in the meantime UKIP could rack up a major win. Polls for the typically low-turnout European parliamentary elections suggest that UKIP could come out on top next month, reflecting the passion the party’s voters feel against E.U. membership compared with the more muddled views in the other major parties.

Clegg proposed the debates with Farage as a way to raise his own profile as an unapologetic defender of the E.U. after four years as the junior partner in a Tory-led coalition government.

Prime Minister David Cameron favors giving Britons a referendum on E.U. membership by 2017, a position that is widely seen as an attempt to mollify the Euro-skeptics in his own party who worry about voters defecting to UKIP.

Cameron once dismissed UKIP as a party of “fruitcakes and loonies and closet racists,” but it has become a serious threat to the Conservative leader’s right flank.

On Thursday, Cameron sought to stake out the middle ground,telling the BBC that both Clegg and Farage have “quite extreme views.”

But there’s little doubt that Cameron and other mainstream politicians had been hoping a Clegg victory in the BBC debate Wednesday would halt Farage’s momentum. Instead, the debate seems to have only given him more fuel.

Clegg on Wednesday night tried to paint the UKIP leader as a reactionary who is uncomfortable with a “compassionate, diverse and modern” Britain and who would rather promote “dangerous fantasies about a bygone era that no longer exists.”

In particular, Clegg hit Farage for opposing gay marriage, questioning climate science and seeking to keep all but the well-to-do from immigrating to Britain.

Clegg also repeatedly criticized Farage for comments in which the UKIP leader said Russian President Vladimir Putin is the world leader he most admires. (Farage has clarified that he admires Putin’s skill as “an operator,” even if he dislikes the man.)

Farage, a natural brawler, seemed to relish his turn in the spotlight even when under attack. He accused Clegg of not trusting the British people to make up their own minds about the E.U., and redirected the Putin accusations into a crowd-pleasing appeal to stop the “endless foreign wars.”

Farage, who turns 50 Thursday, said he not only wants Britain to get out of the E.U., he also thinks the organization should be disbanded. And he hinted darkly that there could be violence if that doesn’t happen, warning that Europeans will no longer tolerate the loss of national sovereignty that comes with being part of a 28-nation union.

“I want the E.U. to end but I want it to end democratically. If it doesn’t end democratically, I am afraid it will end very unpleasantly,” Farage said. “If you take away from people their ability, through the ballot box, to change their futures because they have given away control of everything to somebody else, then I’m afraid they tend to resort to unpleasant means.”