Martin Amis admitted yesterday to feeling racist urges, reigniting a literary spat that in the past month has seen him and his father Kingsley accused of bigotry.

Speaking on the final day of The Times Cheltenham Literature Festival, he told an audience that the charges levelled by the Marxist literary critic Terry Eagleton were “the corniest and laziest second-hand response to Kingsley’s work”, and added that it was “delusional” to pretend that deep-seated inherited prejudices did not linger in some form in most people.

Kingsley Amis, who died in 1995, was mildly anti-Semitic, which his son acknowledged was a “character flaw”, but the family had become less prejudiced with every generation following his grandfather, a “burbling, bumbling racist” who was surprised to see black people driving cars in Washington.

“My grandfather was a racist. My father was a bit dodgy. I think I’m pretty free of racism, but I get little impulses, urges and atavisms now and then,” Martin said. “I can palpably feel that my children are less racist than I am. Their children will be less racist than they are and so it goes on.”

However, he added: “No one can declare themselves free of prejudice. Our tribal instincts have been with us for five million years, so to snap your fingers and say you have grown out of that is idle. You shouldn’t indulge it \ in anyone. But it’s delusional to think that we can shrug it off. It is much healthier to look at it that way and not just announce tremblingly that you are completely free of it.”

The seeds of the row lay in an interview that Amis gave to The Times last year, reflecting on the “Age of Horrorism” as he calls it — the battle against radical Islamism and terror.

In it he said: “There’s a definite urge (don’t you have it?) to say, ‘The Muslim community will have to suffer until it gets its house in order’. What sort of suffering? Not letting them travel. Deportation, further down the road. Curtailing of freedoms. Strip-searching people who look like they’re from the Middle East or from Pakistan . . . Discriminatory stuff, until it hurts the whole community and they start getting tough with their children.”

Professor Eagleton, a Professor of Cultural Theory at the University of Manchester, where Amis recently started work as head of creative writing, found the comments reminiscent of “the ramblings of a British National Party thug”.

This autumn Professor Eagleton wrote a new introduction to his 1991 text Ideology: An Introduction, in which he described Kingsley Amis as “a racist, anti-Semitic boor, a drink-sodden, self-hating reviler of women, gays and liberals”. He added: “Amis fils has clearly learnt more from him than how to turn a shapely phrase.”

Eagleton called other writers who leapt to Amis’s defence last week “stomach churning”. On Friday Amis wrote an open letter to a newspaper stating that his antagonist had “submitted to an unworthy combination of venom and sloth. Can I ask him, in a collegial spirit, to shut up about it?”

Certainly, Kingsley Amis was a provocateur. He hosted “fascist lunches” at Bertorelli’s and loved baiting his liberal-minded friends with references to “nig-nogs”. He also had history with the Cheltenham festival. In 1962 he met the writer Ellizabeth Jane Howard there, leading to an affair that ended his first marriage. He later married her, she recalled in a supportive letter to a newspaper last week, in front of four witnesses: one of whom was homosexual and three Jewish.

Yesterday Martin Amis admitted that he had told racist jokes as a young man, but “it was done playfully”. His wife and two daughters are Jewish.

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