Ukip will adopt a different approach to tackling claims it is racist with a new election campaign strategy featuring black and ethnic minority candidates this week, Nigel Farage said.
The Ukip leader insisted his party would get on the front foot as it fights against claims of racism, as a poll showed some 35% of people felt while the party is not racist, it "does seem to attract some candidates or supporters with racist, extreme or odd views".
More than a quarter of those polled by YouGov said Ukip was a party with "racist views" and "many racist members".
Addressing the claims, Mr Farage said: "Not only am I adamant we are a non-racist party, this week I am going to fight back against it. You will see our election address for the local elections this year and you will see a lot of black, ethnic minority candidates who are proudly standing for Ukip.
"I am going to approach this differently in future."
He added: "I have never believed in the past in positive discrimination, I have believed in treating everybody equally. I have never gone for all female shortlists or whatever.
"But to see what is written every day, describing my party as being racist and homophobic, we will deal with that head-on this week."
Challenged on his views on Romania, Mr Farage said: "If a whole load of Romanian men moved in next door to you, would you be concerned about it? Perhaps you would, yes.
"Because you know, that what has actually happened is we have opened up the doors to countries that have not recovered from communism and I'm afraid it has become a gateway for organised crime - everybody knows that, no-one dares say it."
Mr Farage said he wanted a points-based system for immigration to judge on quality as well as quantity.
Mr Farage acknowledged in the interview, on the BBC One Andrew Marr programme, the party had "made mistakes" in its vetting of members and candidates, highlighting the membership form which tells new recruits the party is not extremist or racist.
But he said all parties have problems with some individual members.
Mr Farage said: "Some people have got through, we should have weeded more of them out - however when you look at the fact we have nearly 2,500 people standing and a handful cause embarrassment, if you looked at the other parties, they haven't just said bad things.
"There was a Liberal Democrat last week, a serving councillor, convicted of racially aggravated assault and that does not make the national news."
In the new polling, Ukip has a three-point lead for this month's European election - but most people think the party contains racists, according to an opinion poll.
Mr Farage's party is on 29%, ahead of Labour on 26%, the Conservatives on 23% and Liberal Democrats on 10%.
But 27% of those surveyed thought Ukip is a party with "racist views" and "many racist members", while 35% thought that, while the party is not racist, it "does seem to attract some candidates or supporters with racist, extreme or odd views".
Some 26% said Ukip is not racist and their "more controversial candidates are just saying the things ordinary people actually think".
The poll came as Ukip was forced to suspend another would-be councillor for expressing extreme views on Twitter.
Harry Perry posted comments on Twitter describing Prime Minister David Cameron as a "gay-loving nutcase", calling Muslims "devil's kids" and homosexuality "an abomination before God".
For the 2015 contest Labour has a three-point lead on 36% over the Conservatives on 33%, with Ukip on 15% ahead of the Lib Dems on 10%.
In response to the threat from Ukip, Mr Cameron has made his commitment to a referendum on Europe a red line issue for any government he might lead after 2015.
The Prime Minister told the Sunday Express the British people deserve "one last go" to get a Europe that that suits them.
He dismissed Ukip's "throw in the towel" approach, instead insisting that he would be able to renegotiate a better deal with Brussels before putting it to a public vote before the end of 2017.
He said: "Other members do not want to see us leave because we bring an enormous amount to the EU, to the economy and policy.
"I'm saying to them that, if you want Britain to stay, there are changes we are going to have to make because, frankly, consent for membership to this organisation is wafer-thin."
:: YouGov polled 1,844 British adults between April 30 and May 1.
Conservative Party Chairman Grant Shapps told the Sky News Murnaghan programme it was important to differentiate between Ukip members and candidates, and the people who vote for the party.
He said: "Every party has to manage who their candidates are, I think it is pretty apparent by this stage Ukip have not done that, they have a remarkable string of individual circumstances that add up to something bigger, which does lead you to have concerns about some of the people involved in that party.
"You don't have to look far to see day in, day out, serious allegations being made which turn out to be true. In the end - and I want to make a very clear distinction between that, what motivates the leadership or others and people who vote for them - I think in the end people should see what motivates the party."
Liberal Democrat deputy leader Sir Malcolm Bruce said it would be "disappointing" for both the party and Britain if its MEPs were wiped out at the election.
He told BBC1's Sunday Politics: "It would be disappointing, not least because we have the most hard-working MEPs of all the British MEPs in terms of attendance and participation.
"The worry we have is that people think the European elections aren't important and that the European Parliament is not important.
"Yet the European Parliament takes decisions that affect us and the people who are working hardest to ensure that British national interests are defended in Europe have been Liberal Democrats.
"So it would be disappointing not just for the Liberal Democrats but for Britain."
He confirmed that the Lib Dems still believed that the UK should adopt the euro in the long term if it becomes "one of the world's leading currencies".
But he added: "We are ruling out Britain joining in the foreseeable future."