Sir Keir Starmer has said he does not believe Nigel Farage or Reform voters are racist - and also refused to label Donald Trump's claim that London wants "Sharia law" as such.
The prime minister told Sky News political editor Beth Rigby the president's claim - made while criticising the capital's mayor, Sir Sadiq Khan, during a UN summit last week - was "nonsense".
Asked if it was racist, considering Sir Sadiq is a Muslim, Sir Keir said: "I have been really clear that the idea that in London we're introducing Sharia law is rubbish."
He said the mayor - who has branded Mr Trump "racist, sexist, misogynistic" - was doing a "very good job", but also pointed to his "very good relationship" with the president.
Sir Keir also insisted he does not think Mr Farage or Reform supporters are racist, after targeting the party in his Labour conference speech and claiming its leader "hates Britain".
Earlier in the week, Sir Keir called Reform's freshly announced immigration policies "racist" and "immoral".
Asked if he thinks Mr Farage is a racist, he said: "No, nor do I think Reform voters are racist.
"They're concerned about things like our borders, they're frustrated about the pace of change.
"So I'm not for a moment suggesting that they are racist."
He said he was "talking about a particular policy", which would see Reform axe the right of migrants to apply for indefinite leave to remain, ban anyone who is not a UK citizen from claiming benefits, and force those applying for UK citizenship to renounce other citizenship.
Reform 'taking country down road of toxic division'
Sir Keir also refused to say whether he thinks Mr Farage is dangerous, saying: "I think the fight at the next election is going to define us as a country for years to come.
"I think it's a dangerous moment for the country."
He said he would not "get into labelling the man".
"I'm talking about the ideas and what he stands for and what I stand for," he added.
"I think that taking our country down the road of toxic division where you don't want to fix problems because if they're fixed, you lose your reason to exist, I think that is dangerous for our country."
Farage: Starmer unfit to be PM
Mr Farage reacted to Sir Keir's speech by accusing him of being "unfit to be the prime minister of our country".
"I used to think the prime minister was a decent man, somebody that I could talk to and chat to," he said.
"We might disagree on our worldview, but I thought he was a profoundly decent human being. I am completely shocked at his behaviour.
"I hope when he wakes up tomorrow morning he feels ashamed of what he has done. This is a desperate last throw of the dice for the prime minister who's in deep trouble, a prime minister who can't even command the support of half of his own party.
"But I'm sorry to say, I now believe he is unfit to be the prime minister of our country."
(c) Sky News 2025: Farage isn't racist, says PM - as he's challenged over Trump's 'Sharia law' comment