Ukip leader reaffirms pledge and says he will resign within 12 hours if party fails to get MPs into parliament in 2015

Nigel Farage has reaffirmed his pledge to stand down as Ukip leader if his party fails to win any seats in the 2015 general election.

He told the BBC's Sunday Politics that, if Labour won the election on a non-referendum manifesto and Ukip failed to get any MPs into parliament, he would resign within 12 hours.

"I would have failed," he said. "I would have spent years trying to achieve this goal. I got into politics not because I wanted a career in politics, far from it, I did it because I genuinely don't think that this European entanglement is right for our country."

Farage first said he would resign if Ukip failed to win a seat in 2015 at a news conference at the Ukip spring conference last month, but he did so in a flippant manner that raised doubts about whether he was being serious.

In his Sunday Politics interview, Farage also said that the former Tory donor, Paul Sykes, has made a sizeable contribution to Ukip. Two weeks ago Neil Hamiltion, Ukip's campaign manager for the 2014 elections, said Sykes had yet to honour his pledge to give money to the party, but Farage said the situation had now changed.

He said: "Paul has made a substantial investment. We are well on our way to a properly-funded campaign."