Ukip leader Nigel Farage has said he is “proud” that his party have claimed a third of all British National party voters.
Mr Farage said his anti-EU party had provided “frustrated” people with a more suitable alternative to the far-right BNP.
Speaking at an event at London’s Chatham House on Monday, he also said that Ukip will now focus its energies on Labour strongholds in the run-up to May’s local and European elections – because Tory supporters had already been won over.
And Mr Farage denied taking “extremist” positions on immigration, pointing out that former BNP members had been banned from joining his party.
“We want no truck with the BNP types at all,” he said.
“What we did, starting with the Oldham by-election in the North of England is for the first time ever try to deal with the BNP question by going out and saying to BNP voters, if you are voting BNP because you are frustrated, upset with the change in your community, but you are doing it holding your nose because you don't agree with their racist agenda, come and vote for us.
"I would think that we have probably taken a third of the BNP vote directly from them.
“I do not think anyone's done more... to damage the BNP than Ukip, and I am quite proud of that.”
Support for the BNP has been dwindling since its height in 2009, when the party secured 940,000 votes in the European elections.
Mr Farage conceded that it could be a matter of “luck” whether Ukip won a Westminster seat next year, but he said he was confident about the party’s performance in May.
“We are going to be spending the bulk of our money in the next eight weeks in the big Midlands and Northern cities, targeting the Labour vote,” he said.
“I think that Conservatives who are going to vote for Ukip, or even lend their vote to Ukip, on 22 May who live in Dorset have made their minds up already."
His comments came as Labour Shadow Chancellor Ed Balls warned that Britain would be reckless to walk away from the European Union and that an exit would have a detrimental impact on jobs and investment.
Conservative Prime Minster David Cameron has promised an in/out referendum by 2017 if his party wins next year’s election.
The promise of a referendum is likely to appeal to Eurosceptic voters who might otherwise defect to Ukip.
Additional reporting by agencies