UKIP is against "white immigration" from eastern Europe but in favour of "immigration from the Third World", BNP leader Nick Griffin has claimed.
On BBC Radio 4's Today programme, Mr Griffin criticised UKIP's immigration policies, which he said would allow "300,000 more people into this country every year from Africa and Asia".
"The BNP position is: we don't want Poles, we don't want Pakistanis. The country is full," he said.
UKIP declined to comment on the claims.
Mr Griffin said: "UKIP's claim is that they would limit immigration, but their actual policy is to limit it to net immigration of 50,000 a year."
In practice, this would entail allowing one migrant from what UKIP thought of as "our traditional sources of immigration... namely Africa and Asia" to settle in the UK for every British national who emigrated - "and that is over a quarter of a million people every year... plus 50,000", he said.
"UKIP are saying that they don't want white immigration - eastern European immigration. They want immigration from the Third World, black or brown immigration.
"We're saying that we don't want white, black, brown or green, because the country is full and immigration is unfair on the British people."
'Murdering old terrorist'
In the interview, Mr Griffin also claimed that he had "never denied the Holocaust".
According to transcripts of a police interview from 1998 - when Mr Griffin was being investigated on suspicion of race hate charges - which have been released under freedom of information laws and published in the Guardian, he said: "The allegation that there was a systematic and deliberate policy whereby six million Jews were gassed to death is for a variety of forensic and common sense reasons, utter nonsense."
But Mr Griffin told the Today programme's Justin Webb: "Gentile liberals and lefties such as yourself exploit things that happened decades and many decades ago to use as a moral club to prevent a proper, sensible discussion about immigration now."
He accused his interviewer: "What you're trying to do is to set the British people up as Pavlovian dogs, so that when they hear Nick Griffin, they hear the Holocaust. It's disgraceful."
Mr Griffin also stood by his past comments that the late South African President Nelson Mandela was a "murdering old terrorist".
"That is what he had been. That is what he was," he said.
His use of the word Fenian, a derogatory term about Catholics, on Twitter in 2012 had just been "banter" and was not aimed at Catholics in general, he added.
Although a UKIP spokesman said the party would not be commenting on Mr Griffin's characterisation of his party's policies, UKIP leader Nigel Farage addressed his critics at an election rally in Westminster last week.
"I don't care what you call us," he said, "but from this moment on please do not ever call us a racist party. We are not a racist party."