Does UKIP's big win herald a big change in British politics?

Was it just another protest vote, or something more?

That is the question being asked among Britain’s political class about the success of anti-Europe party UKIP in the weekend's European Parliament elections.

Under leader Nigel Farage, the Euroskeptic party doubled its members in the European Parliament to 24, compared to 20 for Labour, 19 for the Conservatives, and just one seat for the pro-Europe Liberal Democrats, whose vote collapsed. The victory has sent shockwaves through the established political parties, with particular pressure on Lib Dem leader Nick Clegg to resign.

Describing the outcome as the "most extraordinary result" in British politics in the past 100 years, Mr. Farage said his "people's army" now aimed to win UKIP's first Westminster member of Parliament next week, in a by-election in the Nottinghamshire constituency of Newark. Such a victory would be a huge turnaround for UKIP, which finished fifth in the 2010 Newark election, far behind the Conservative winner, who won handily.

Today Prime Minister and Conservative leader David Cameron urged EU leaders to heed the UKIP and other anti-Europe results across the continent ahead of a Brussels summit. He called for reform of EU institutions and said it could not be "business as usual" in the wake of the European Parliament results.

But despite the UKIP success, it is unclear whether the victory indicated a mere protest vote or a more significant change in voting patterns ahead of next year’s general election.

Alistair Clark, a senior lecturer in politics at Newcastle University, is skeptical whether UKIP could replicate the results in 2015, especially under Britain’s "first-past-the-post" electoral system. He says it would require a huge swing among voters for UKIP to actually win seats in the British parliament when voters tended to vote on more domestic-type issues such as the economy.

However he said the results would change the debate on Europe in the UK. “It will make making the case for Europe harder, as you’ve seen from the reaction to Tony Blair trying to make the case on the [BBC Radio Four’s] Today program this morning. UKIP have traditionally taken votes from the Conservatives but in these European elections it’s been Labour and the Conservatives," Dr. Clark says.

“We have always had an awkward relationship with Europe going back to Margaret Thatcher, but these UKIP results will force the traditional parties to review their European policies. It’s already happening in Europe with President Hollande talking about reform, but I think UKIP will struggle in a general election.”

Roger Scully, a professor of political science at Cardiff University, said the weekend results raised new questions for Britain’s established parties but the biggest test for UKIP was next week’s Newark by-election.

"For Labour, they might have to change their anti-referendum policy and think about supporting one," Professor Scully says. “For the Conservatives, the Euroskeptic wing might become more hostile to Europe, which will put more pressure on Cameron, which could become overwhelming.” 

He says it is plausible that UKIP could win five to 10 seats in next year’s general election if the party concentrates its resources on 20 to 30 constituencies as planned. But he does not envisage wider success. “I think UKIP will come under far more scrutiny in a general election which is different from a European election where voters are prepared to vote for ‘crazier’ candidates knowing that there’s little connect and consequences in Europe."

But “If UKIP do win seats," he adds, "that could be crucial in a tight election and Cameron might be forced to do a deal. If that’s the case UKIP could call for a referendum earlier, say 2016 rather than 2017.”