LONDON - The leader of Britain's rising right-wing anti-EU party on Friday promised a political "earthquake" with victory in next year's European elections, a challenge that could threaten David Cameron's hopes of a second term as prime minister.
Nigel Farage, head of the anti-mass immigration UK Independence Party (UKIP), said it would overturn decades of dominance by Britain's main three parties, the Conservatives, Labour and the Liberal Democrats.
Once derided by Cameron as "fruitcakes, loonies and closet racists", UKIP has increased its support to around 10 percent, according to pollsters YouGov, after taking just three percent of the vote in the last national election in 2010 and failing to secure a single parliamentary seat.
Farage said if UKIP wins a majority of the UK seats in the 2014 election for European Parliament it would effectively be a condemnation of "open-door immigration" and Britain's membership in the 28-nation bloc, which the main parties generally support.
UKIP had a 16.5 percent share of the vote at the last European elections in 2009, securing 13 of Britain's 72 seats.
"We can come first and cause an earthquake," Farage told his party's annual conference on its 20th anniversary. "We're changing the face of British politics."
Cameron has already promised to hold an "in/out referendum " before the end of 2017 in a move seen as an attempt to placate Conservative eurosceptics and take the advantage from UKIP. UKIP wants to leave the EU immediately.