UKIP leader Gerard Batten has accused his predecessor Nigel Farage of "smearing" the party, while defending his own links to Tommy Robinson.
He said Mr Farage, who launched the rival Brexit Party on Friday, wanted to "discredit" UKIP by claiming Mr Batten was condoning violence by working with the ex-English Defence League leader.
He said UKIP had always been, and would remain, a "non-racist" organisation.
While not a member, Mr Robinson was a "useful source of research", he said.
Mr Farage quit UKIP earlier this year in protest at the direction of the Eurosceptic party, saying it had become obsessed under Mr Batten's leadership with the threat Islam posed to UK society.
Launching his new party on Friday, Mr Farage said the UKIP leader's decision to appoint Mr Robinson as an adviser on grooming gangs and prison conditions tarnished his former party and associated it with "extremism, violence, criminal records and thuggery".
Mr Robinson, whose real name is Stephen Yaxley-Lennon, has been banned from Twitter, Instagram and Facebook for violating its policies on hate speech.
The political activist has served prison sentences for a number of offences but is regarded as a freedom of speech champion by his supporters.
He was jailed for contempt of court last year, a conviction that was later quashed on procedural grounds.
'Information and research'
Mr Batten defended his association with Mr Robinson, saying it had not stopped the party from attracting 11,000 new members from a range of backgrounds since he became leader.
"Nigel has known me for 27 years. He knows exactly where I stand on things just as I know where he stands on things.
"He knows that this is a smear. This is a device he is using to try and discredit UKIP and enhance the chances of his own new party... What he is saying is a complete smear."
Mr Farage, he suggested, had employed a former member of the National Front when he was leader on the basis he was no longer associated in any way with the fascist organisation.
"I have lots of people who advise me, some of which are not members of UKIP," Mr Batten added.
"Tommy Robinson is not far-right... and does not have far-right views. He is someone who can give some information and research which is useful to me.
"We have always been a democratic, non-racist party. That has always been in our constitution and that is exactly the way we are going to keep it.
"It is very odd in this day and age when you get called far-right, when what you have spent the last 25 years trying to do is to return government to our own democratically elected Parliament."
Mr Batten also defended Carl Benjamin, a possible UKIP candidate in next month's European elections, who posted a message on Twitter in 2016 to Labour MP Jess Phillips which said: "I wouldn't even rape you."
Asked why he had not been thrown out of the party, Mr Batten described Mr Benjamin as a "classical liberal" and said he thought the message had been "satirical" in nature.
"I don't know the exact context of that and I certainly don't condone any remarks like that, but he is not a bad person as he is trying to be portrayed," he said.
"He is a proponent of free speech. The context that he said it was satire against the people he was saying it about. He was not actually making a literal statement."
Ms Phillips, who has spoken out on behalf of rape and domestic violence victims in Parliament, said it was right for the UKIP leader to have been challenged on the issue, and she was considering getting an "army of feminists" to campaign in the area that Mr Benjamin was standing.
I see that people talking about if they would or wouldn't rape me has been discussed on #Marr this morning. UKIP claim it is satire to discuss my rape. I didn't see it I was eating pancakes with my sons and nephews. We are all flesh and blood.— Jess Phillips (@jessphillips) April 14, 2019