Rishi Sunak said a racial slur against him by a Reform UK canvasser “hurts and it makes me angry” and that party leader Nigel Farage “has some questions to answer”.
Campaigners for Mr Farage’s party were recorded making racist comments, including about the Prime Minister who is of Indian descent.
Mr Sunak on Friday said: “My two daughters have to see and hear Reform people who campaign for Nigel Farage calling me an effing p***. It hurts and it makes me angry, and I think he has some questions to answer.
“And 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.”
Speaking on a campaign visit to a school in Teesside, he continued: “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.”
The footage, made by an undercover Channel 4 reporter, showed Reform campaigner Andrew Parker using the racist term 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 are paedophiles.
A spokesman for Essex Police said the force is “urgently assessing” the comments “to establish if there are any criminal offences”.
Mr Farage sought to distance himself from the comments, saying the canvassers’ language was “vulgar, drunken and wrong” and that they had been kicked out of the party.
He told ITV’s Loose Women: “They had watched England play football, they were in the pub, they were drunk.
“People when they are drunk often turn quite nasty.”
Asked whether he would take action against them, he said: “They’re gone.”
Sir Keir Starmer said he was “shocked” by the “clearly racist” footage and that the Reform UK leader faces a “test of leadership”.
The Labour leader told BBC Breakfast: “You have to ask the question why so many people who are supporting Reform seem to be exposed in this particular way.
“It’s for a leader to change his or her party, to make sure the culture is right, and the standards are understood by everybody within the party.”
Mr Farage used reports that Mr Parker was a part-time actor to suggest “this whole thing was a complete and total set-up”.
But Mr Parker told the PA news agency that his volunteering for Reform was separate from his acting job, adding that he had been “goaded” into making the comments caught on camera.
Channel 4 hit back at the claims Mr Parker was a paid actor, with a spokesperson for the broadcaster saying: “We met Mr Parker for the first time at Reform UK party headquarters, where he was a Reform party canvasser.”
Mr Sunak also condemned Mr Farage’s previous praise of Andrew Tate as an “important voice” for men.
The online influencer has faced charges of human trafficking, rape, and forming a criminal gang to sexually exploit women.
The Prime Minister said: “Andrew Tate isn’t an important voice for men. He’s a vile misogynist. And our politics and country is better than that.”
It is not the first time Mr Farage has faced questions over some Reform UK candidates and the party has withdrawn support from several people prior to the General Election after investigations uncovered previous comments they had made.
On Thursday, the Reform leader claimed his candidates “in most cases” were “just speaking like ordinary folk”.
He added: “In some cases one or two people let us down and we let them go.”
On the same day, the Guardian reported that Reform had withdrawn its support for Raymond Saint, its candidate in Basingstoke, who allegedly appeared on a list of BNP members published on the website WikiLeaks more than a decade ago.
Mr Farage has previously said he had an “absolute rule” to block anyone linked to the BNP or similar organisations from being a member of his party.
Asked why people who espoused racist or homophobic views supported his party, the arch Brexiteer told Loose Women: “Ironically, I think because we destroyed the BNP, they haven’t got the BNP to go to any more.”
But other candidates who have been criticised for their language have retained Reform’s support, including Leslie Lilley, the candidate in Southend East and Rochford, who reportedly said he would “slaughter” migrants and “have their families taken out”.