A Ukip council candidate who posted an offensive tweet about the comedian Lenny Henry resigned his membership of the party after it was "mutually agreed this would be the best course", a Ukip spokesman said.
William Henwood, who suggested Henry should emigrate to a "black country", was due to stand for the party in next month's election in Enfield, north London.
Ukip council candidate William Henwood has resigned his membership of the party following a controversy over offensive comments about comedian Lenny Henry.
Labour voters are defecting to Ukip because the party has become "very middle class", a former adviser to Ed Miliband has said.
Lord Glasman, who was made a peer by Mr Miliband, said Ukip's success would hit Labour "in the heartlands".
He told The Times that the last election saw a sharp decline in Labour's traditional working class base.
"The Labour middle class vote held up (in 2010). It was the working class vote that died. These are often people who are earning, who have jobs, but they don't see Labour as representing their interests."
Bad publicity surrounding the UK Independent Party is having no affect, the party's deputy chairman told ITV News. Neil Hamilton said that it showed the "difference between ordinary, normal people in the country, and those in the 'Westminster bubble'".
Mr Hamilton added that claims surrounding Ukip candidate William Henwood would be investigated, and that if he made "false statements" over the reported racist remarks, he would be "turfed out".
The Health Secretary has criticised a Ukip candidate for posting tweets that suggested comedian Lenny Henry should leave Britain to live in a “black country.”
Jeremy Hunt said the comments made by William Henwood, who is standing in a council election, were "absolutely disgusting".
Speaking to BBC radio programme Five Live, Mr Hunt said: "I think [Nigel Farage] needs to make it absolutely clear that it's not Ukip's view".
Asked if he thought the comments were racist, Mr Hunt replied: "Yes I do. I think it is and that's why I'd like to hear a very clear denunciation of that from Nigel Farage.
"I think it's totally unacceptable and (Lenny Henry) is as British as you and I are."
A Ukip spokesman said that any breach of party rules would be investigated, but also criticised the exposure of candidate William Henwood's tweet by "the other parties."
A spokesman for the party told the BBC:
Ukip is facing a fresh backlash over comments made on Twitter by one of its candidates who suggested Lenny Henry should emigrate to a "black country" in response to a speech by the actor and comedian that said ethnic minorities were under-represented on British television.
William Henwood, who is standing in a council election, told the BBC: "I think if black people come to this country and don't like mixing with white people why are they here? If he (Henry) wants a lot of blacks around go and live in a black country."
Ukip member and candidate for election in Enfield, William Henwood, has suggested on Twitter that the comedian Lenny Henry should leave Britain to live in a “black country.”
He was responding to tweets from Henry suggesting there were not enough ethnic minority faces on the BBC.