Anti-immigration politician Nigel Farage has criticised a worker for his Reform UK party who suggested migrants crossing the English Channel in boats should be used for “target practice”.

But Farage later suggested that the episode had been a “stitch-up” by Reform UK’s opponents.

Party activist Andrew Parker was heard suggesting army recruits with guns should be posted to “just shoot” migrants landing on beaches, in recordings made by an undercover reporter from Channel 4.

He also used a racial slur about Prime Minister Rishi Sunak, who is of Indian descent.

Another campaign worker called the LGBT pride flag “degenerate”.

Reform UK said it had cut ties with the two men.

Farage said he was “dismayed” by the comments and called some of the language “reprehensible”.

“The appalling sentiments expressed by some in these exchanges bear no relation to my own views, those of the vast majority of our supporters or Reform UK,” he said in a statement.

Sunak said the slur used by Parker “hurts and it makes me angry,” especially since his two daughters had to hear it.

He said Farage “has some questions to answer”.

“As prime minister, but more importantly as a father of two young girls, it’s my duty to call out this corrosive and divisive behaviour,” Sunak said on Friday on the campaign trail in northeast England.

On Friday, Farage sought to cast doubt on the Channel 4 report after it emerged that Parker is an actor.

“Folks, this is the biggest stitch-up I’ve ever seen in my life,” he said in a video for supporters.

Parker confirmed that he is an actor but said that he volunteered for Reform UK because he believes in its message.

Channel 4 News said it stood by its “rigorous and duly impartial journalism”.

“We met Mr Parker for the first time at Reform UK party headquarters, where he was a Reform party canvasser,” the channel said in a statement.

Channel 4 News said that Parker was covertly filmed by an undercover investigator inside the Reform UK campaign and that no one was paid for the footage.

The party is running candidates in hundreds of seats for the United Kingdom election on July 4, aiming to siphon off voters from the dominant Conservative and Labour parties.

It has disowned several candidates after media reported on their extremist ties or offensive comments.

Speaking at a campaign event on Thursday, Farage said that “one or two people let us down and we let them go”.

But he said in other cases of criticised comments, “in most cases they’re just speaking like ordinary folk”.

—AAP