Ofcom has said it will not investigate Channel 4 after Nigel Farage's Reform UK accused the broadcaster of “election interference” and using an actor as a “secret agent” in a sting operation.

Ofcom will not investigate Channel 4 News after Nigel Farage and Reform UK claimed the channel used an actor as a “secret agent” in its covert investigation into his campaign.

The UK watchdog said it had received more than 270 complaints about Channel 4 News' programme Undercover Inside Reform's campaign, in which a canvasser named Andrew Parker was filmed using a racial slur to describe Prime Minister Rishi Sunak.

After the investigation was broadcast, Reform Party secretary Adam Richardson said in a letter to the Electoral Commission that it was “absolutely obvious that Mr Parker was an intruder on Channel 4's news programme”, adding that the programme “can only be described as election interference”.

But on Wednesday, Ofcom said that after “urgently” assessing the complaints against the required accuracy, required impartiality and infringement rules under the Broadcasting Code, “we concluded that they did not raise substantive issues that warrant further investigation”.

A Channel 4 News spokesperson said: “Since this report was broadcast, Channel 4 News has stood firmly behind its accurate, rigorous and duly impartial reporting, which speaks for itself.”

The dispute with Channel 4 stems from an undercover report on activists involved in Mr Farage's bid to win a Westminster seat in the eighth attempt.

Channel 4's statement continued: “Ofcom's decision underlines the integrity of Channel 4 News' journalism and its high editorial standards.

“The programme will continue to refute any allegations that we – or the production company we worked with – knew or paid Reform UK’s solicitor, Mr Andrew Parker.

“We first met Mr Parker at Reform UK's campaign headquarters in Clacton, and he was secretly filmed as part of the undercover investigation.”

The footage shows Mr Parker using racist terms about Mr Sunak and suggesting migrants should be used as “target practice”.

Another canvasser described the pride flag as “degenerate” and suggested members of the LGBT community were paedophiles.

It comes as Mr Farage is embroiled in a row with the BBC, claiming the audience for Friday's Question Time special was “rigged” and refusing to appear on flagship show Sunday With Laura Kuenssberg unless the corporation apologises.

He said the members of the public “were not ordinary citizens”, adding: “They personally selected a prominent pro-Palestinian activist and even a BBC television director to attack me.”

Attending a protest does not prevent someone from asking to be in the audience. It is understood that no BBC staff were in the audience.

A BBC spokesperson said: “We refute these allegations. The audience for last night's question time consisted of broadly similar levels of representation from Reform UK and the Green Party, with other parties equally represented.”

“There were also a number of people, with very different political views, who had not yet made up their minds.”

Reform UK deputy chairman Ben Habib has distanced himself from Andrew Parker's comments about the Prime Minister.

He said Andrew Parker, who was filmed using a racial slur to describe Rishi Sunak, was a “disgusting human being”.

Habib said he would “absolutely abhor any racism” within the party and suggested Mr Parker had presented himself as a “gammon” character in Channel 4 footage recorded by an undercover reporter.

Speaking to BBC Radio 4's PM programme, he said: “(Mr Parker) is a disgusting human being if he stands by what he said, absolutely foul language, unacceptable behaviour, unacceptable feelings.

“We have filed a complaint with the Electoral Commission and we will get to the bottom of it.

“It's a coincidence, I think, that raises a lot of questions: that he was an actor, that he used a voice when he was knocking on doors that wasn't his natural voice, and that he was bombastic.

“Exactly the sort of character that someone – if you've heard the expression – might want to attribute to what they call a gammon.”

Parker was also filmed saying the reform would turn all mosques into Weatherspoons pubs and suggested asylum seekers trying to come to Kent from France on small boats should be shot on the beach by young British Army recruits as “target practice”.

Parker, a divorced father-of-one from Bishop Stortford, Herts, who is a part-time actor, refused when asked three times whether he had been paid to infiltrate Reform UK to make their volunteers appear racist.

Speaking exclusively to MailOnline, Mr Parker said he had been set up by Channel – but added: “I'm not going to say anything, I think the best thing I can do is not say anything at all.

“I'm getting phone calls non-stop and to be honest it's making me sick and it's not fair to me. It's really causing me a lot of stress and I really can't take it anymore.”

“I was set up, it's as simple as that, the guy was laughing and joking about it the whole time.

“He pretended to be part of the Reform Party campaign team. It was just a joke and it got ridiculous.

“We were laughing and joking like guys laugh and joke, that's all. I feel a bit stupid, but I'm not used to this kind of thing in the media.”