Good evening. Nigel Farage has faced repeated questions from a BBC audience about the racist language used by a canvasser for Reform UK about Richie Sunack. Mr Farage refused to apologize, saying it was a set-up and a deliberate attempt to smear his party. Mr Sunack, who is of Indian origins, said the language made him hurt and angry, and that Nigel Farage had questions to answer. The racist comments were secretly filmed and then broadcast by channel 4, while activists were campaigning for reform UK in Clacton, where Mr. Farage is standing. Our political correspondent, Joe Pike, is in Westminster for us now. Joe.

Rita, Nigel Farage's surprise entry into this election revitalized, re-energised reform and seemed to give them a poll boost as well. But as we saw from the Question Time Leaders special tonight that he appeared on, that drip drip of constant allegations concerning first candidates, and now campaigners does seem to be having an impact, not just on Mr. Faraj's own team. I've detected a certain nervousness there. But also, as we saw this evening, he seemed to be disowning some of his own candidates live on air. And a warning, my report contains offensive language.

I'd like you to please to welcome the leader of Reform UK, Nigel Faraj.

He's attempting a fight back as his party is hit with yet more accusations of racism. What is it about you and your party that attracts racists and extremists, whether you say you want them or not?

I've done more to drive the far right out of British politics than anybody else alive. I took on the BNP just over a decade ago. I said to their voters, If this is a protest vote, but you don't support their racist agenda, don't vote for them, vote for me. We destroyed them.

Asked live on air about reform candidates who've made offensive comments, Mr Farage seemed to dismiss those standing.

I inherited a startup party. Remember, I've been doing this- Why are they still standing as your candidates? Well, they're not. They've been disowned. In most cases, they've been disowned.

But now it's not just candidates, but campaigners that have been causing problems. One, seeing a pride flag on a police car implied gay people were pedophiles.

You see that fucking degenerate flag on the front bonnet? What the old bill doing promoting that flag is without catching nonsense, not promoting the flag.

Another suggested the army should shoot illegal immigrants. With guns on the beach, target practice, fucking... Just shoot them. And he used a racist slur to describe Richie Sunak.

I feel like he got in. He was good, isn't he?

You tell me...

He just went.

Andrew Parker said he'd not told Nigel Farage about his views, he brought reform into disrepute.

When my two daughters have to see and hear reform people who campaign for Nigel Farage calling me an effing, it hurts and it makes me angry. I think he has some questions to answer. I don't repeat those words lightly. I do so deliberately because this is too important not to call out clearly for what it is.

Earlier today, we caught up with the reform leader. Hi, Nigel. How are you doing?

What's the thing?

He seemed keen to focus on one of the campaigners who he claims was acting.

From the moment he arrived in the office at Clackton last Saturday, and he bowled up and spoke to me, he was rough speaking.

You think he was faking it?

He was acting from the moment When he came into the office. I 100% believe this whole thing is a total setup.

Andrew Parker has told us tonight he doesn't want to comment. He has done some acting in the past, but today we found no evidence he was acting in the covert recording. Channel 4 News have said, We strongly stand by our rigorous and duly impartial journalism, which speaks for itself. We met Mr. Parker for the first time at Reform UK Party headquarters, where he was a reform party canvasser. We did not pay the reform UK canvasser or anyone else in this report. Mr. Parker was not known to channel 4 News and was filmed covertly via the undercover operation. Nigel Farage has been trying to get here for decades, but he and his team know the distractions of the past couple of days have the potential to damage their campaign at precisely the moment when many floating voters are finally making up their minds.

That's the future that I foresee.

I I'm afraid I have to cut you off there, Nigel.

Forgive me. He has survived many similar storms before. Will Nigel Farage weather this one, or will it do damage to his party next week? Joe Pike, BBC News.

Adrian Ramsey, the co-leader of the Green Party appeared on the BBC's Question Time Leader Special tonight, where he was asked about the day-to-day cost of the party's plans to combat climate change in, for example, transport.

I think most people want to do the greener option, but the greener option has got to be the cheaper and more convenient option as well. How would you make it cheaper? At the moment, there are huge subsidies that go into the aviation industry, whilst we have some of the most expensive rail prices in Europe. One of the things we would do is to bring the railways back into public ownership, which I think people would really like to see.