Rishi Sunak has described himself as being “British, English and British Asian” in a riposte to increasing racially charged language used by figures on the right.

The UK’s first British Asian prime minister was speaking after his identity was questioned in recent debate sparked by a claim by the podcaster Konstantin Kisin that Sunak was not English because he was a “brown-skinned Hindu”.

Suella Braverman, the London-born Reform MP and former home secretary, later appeared to give credence to Kisin’s claims by saying that she was not English and questioning whether others born in the country could necessarily have that identity.

More recently, Matthew Goodwin, Reform UK’s candidate in the upcoming Gorton and Denton byelection, refused to disown a claim that UK-born people from minority ethnic backgrounds were not necessarily British.

Speaking out for the first time since those interventions, the Southampton-born former Conservative leader said the racism directed at him and his siblings was “seared in his memory” and warned against Britain “slipping back” to a time when racism was more overt.

Sunak was giving evidence to the Independent Commission on Community and Cohesion, co-chaired by Sajid Javid and Jon Cruddas, which aims to speak to millions of people to try to improve cohesion after the Southport tragedy and riots.

“I think there has been – what I describe it as – is a bit more ‘shock jockery’, recently … as people are saying outrageous things to get attention,” said Sunak, when asked if there had been shifting of the “Overton Window”, a term for the range of ideas and language that are deemed acceptable in mainstream debate.

“That’s one of my worries about the attention economy, or whatever you want to call it, and how that works now, and how we consume media, is that it rewards people for that kind of provocative, bigoted language, whatever that language might be. And I think that that is just a concern of mine. It’s something that, sadly, we’re seeing a bit more frequently as a result.”

Sunak returned to past comments he has made about how he and his siblings had faced racism growing up in Southampton, adding: “I haven’t a brilliant memory on most things, but that is really seared in my memory, because racism stings in a way that other things don’t.”

Referring to Javid, who has also addressed the issue in his recently published memoir describing the racism he experienced in 1970s Rochdale, Sunak said they would agree such experiences were “less common” today.

But he added: “There’s always more we can do. And I definitely wouldn’t want us to slip back into a world where racist language was heard regularly on the street, or considered permissible on TV.”

The commission is being facilitated by the Together Coalition, founded by Brendan Cox, the husband of the Labour MP Jo Cox, who was murdered by a far-right extremist.

Sunak, who remains the MP for Richmond and Northallerton in North Yorkshire, said: “We’re all British, and underneath that, or alongside that, you can have lots of different identities that don’t come into conflict with that. Of course you can.

“I’m British, I’m British Asian, I’m British Hindu, English. Sotonian – what we call people from Southampton, and an apprentice Yorkshireman.”

On immigration, Sunak said that, with hindsight, he wished he had implemented measures to bring down numbers sooner.

On the tensions that spilled over into street violence in 2024, he said it was “evident that something has gone wrong” and that it was made worse by Islamist extremists and the far right, which were “feeding off each other”.

It was “a lie” that Britain was a racist country, Sunak said, citing Javid’s career and his own, and adding that his successor as Tory leader is “a Black woman who grew up in Nigeria”.

Sunak was speaking after a speech by the prime minister, Keir Starmer, earlier in the week in which he addressed themes including “British values” and warned against allowing migration policy to be exploited “by people who think whiteness is the same thing as Britishness”.