Fewer than 15 pupils each year went on to university from Peers comprehensive in Oxford. But Mr Brighouse, 40, son of London schools commissioner Tim, and now a professor of philosophy at the University of Wisconsin, believes the non-academic environment enabled him to flourish academically.

“People find it shocking that I, who became a professor, went to that school,” he said. “But I don’t have any doubts that I benefited more from the comprehensive than the grammar.

“Grammar schools get a lot of academic kids, and they can coast on that.

But at Peers there was a smaller group of academic kids, so we got more attention from the teachers.”

His parents moved to Oxford in 1979 when his father became chief education officer in Oxfordshire and he had to transfer schools. Having sat his O-levels at a selective grammar, he deliberately chose a very different sixth form.

“Any middle-class kids at my school were the children of parents who were making a political choice,” he said.

“But I didn’t feel like a pawn to my parents’ political beliefs. I shared their beliefs and wanted to act on them.”

He was aware that his desire to learn left him in the minority at Peers.

But, while there were a number of trouble-making pupils, he does not recall being singled out for bullying.

“I suspect I’d have had more fun at grammar school. There was a cricket team and a school orchestra I could have joined.

“But I wasn’t a particularly tuned-in kid. I wasn’t responsive to peer pressure. I probably did get teased, but I didn’t notice it very much.”

Nor were his academic aspirations disrupted by unruly pupils. At the time, he said, teachers commanded greater respect in the classroom, so were better able to maintain order.

And he insists that his convictions, unlike those of Diane Abbott, are unlikely to evaporate in the face of parental responsibility.

“Private schools contribute to social injustice. There would have to be very good reasons for switching over to that side. It’s a line I couldn’t cross.”