Theresa May has told the BBC it needs to explain its decision to broadcast a joke about throwing acid at politicians.

Brexit Party leader Nigel Farage has accused Jo Brand of inciting violence following the comment on a Radio 4 show.

The comedian, 61, was appearing on Victoria Coren Mitchell's Heresy on Tuesday night and joked about throwing battery acid at politicians.

In reply to a question about the state of UK politics, she suggested that protesters who have recently thrown milkshakes at right-wing figures including Mr Farage could instead use battery acid.

“Certain unpleasant characters are being thrown to the fore and they're very, very easy to hate and I'm kind of thinking: 'Why bother with a milkshake when you could get some battery acid?” she said.

"That's just me. I'm not going to do it, it's purely a fantasy, but I think milkshakes are pathetic, I honestly do, sorry."

In a tweet on Wednesday Mr Farage, who is the leader of the Brexit Party, accused Brand of inciting violence although he did not say who against.

He wrote: "This is incitement of violence and the police need to act."

And Brendan Cox, whose MP wife Jo was murdered in 2016, said: “I dislike Nigel Farage’s politics profoundly, but I don’t think throwing stuff at politicians you disagree with is a good idea. It normalises violence and intimidation and we should consistently stand against it.”

In a tweet on Wednesday Mr Farage, who is the leader of the Brexit Party, accused Brand of inciting violence although he did not say who against.

He wrote: "This is incitement of violence and the police need to act."

And Brendan Cox, whose MP wife Jo was murdered in 2016, said: “I dislike Nigel Farage’s politics profoundly, but I don’t think throwing stuff at politicians you disagree with is a good idea. It normalises violence and intimidation and we should consistently stand against it.”

Ms May’s official spokesman said the prime minister agreed with Mr Cox.

“The prime minister has been repeatedly clear that politicians should be able to go about their work and campaign without harassment, intimidation or abuse,” said the spokesman.

“It is for the BBC to explain why it considers this to have been appropriate content for broadcast.”

The trend of hurling milkshakes at right-wing politicians began when viral footage showed English Defence League founder Tommy Robinson having one thrown over him in Warrington.

Since then, several other members of the public have repeated the protest.

Nigel Farage on Jo Brand's battery acid comments

Last month Mr Farage was covered in milkshake during a campaign walkabout in Newcastle city centre.

Broadcasting watchdog Ofcom said that, as of Wednesday afternoon, it had received 19 complaints about the episode in question.

At the end of show, Coren Mitchell said she hoped Brand's remarks had not caused offence but added that the radio series had been set up to "test the boundaries of what it's OK to say and not say".

The quiz host and television personality, 46, later responded to Mr Farage on Twitter, accusing him of double standards.

She wrote: "Nigel! I'm genuinely disappointed; we don't agree on everything, but I would totally have had you down as a free speech man. Especially when it comes to jokes."