Who, in recent times, has had a more controversial education than James Thompson, the son of the Labour MP Diane Abbott? In 2003, aged 12, he was forced publicly to defend his mother after she sent him to the £10,000-a-year City of London School. Now, Thompson has made his way to Tema, Ghana, to study at the SOS-Hermann Gmeiner International College (£3,000 a year fees, plus £2,400 for board). “Couldn’t he have got in touch with his African roots in Hackney?” wrote one anti-Abbott commentator online.

Professor Gus John, a fellow of the Institute of Education and a leading commentator on race and education, is more understanding. “I think that most black children growing up in this country, irrespective of whether they go to a private school or a state school, should have an opportunity to go to school in a black country that is of some significance to their heritage,” he says. “It’s very easy to form the view that knowledge is valid only when it comes from a European perspective. Being schooled in black institutions of learning helps young people to get not just a sense of their own identity, self-esteem and history, but also an alternative world-view.”

But what does it say about our state education system if even a left-wing Labour MP does not want her son to use it? Poverty of ambition, socioeconomic challenges relating to crime and single-parent families, institutional racism and under-resourced schools are just some of the factors that contribute to low educational outcomes for many children of African and Caribbean origin. However, as the son of a Cambridge-educated politician, James was never in any danger of being one of the 70 per cent of black boys in London who leave school without five GCSEs graded A*-C (he got 11 A* grades). The inequalities in our education system are primarily about class. Race just compounds the issue.

In joining the ranks of African and Caribbean parents who send their children abroad for at least part of their education, Abbott embodies the aspirations of many black parents. “This country treats the underachievement of black children as if it is in their DNA,” says Professor John. “But children schooled in the Caribbean and Africa learn they can excel, because quite simply nothing less is expected of them.”

The writer, poet and publisher Nii Ayikwei Parkes believes he and his brother were rescued from underachievement when the family moved back to Ghana. “The teachers at my brother’s primary school told my father that he should go to an educationally subnormal school, as they called it in the Seventies, because they thought that he was slow. He was just quiet, but the tragedy is that a lot of parents in the same situation probably took that advice.”

After studying at Achimota School, one of Ghana’s most prestigious institutions, Parkes’s brother took an MBA in the US and became an investment banker. “In Ghana, you are surrounded by images of successful black people: the newsreaders are black, the pilots are black, the doctors are black. Success is normalised.”

But what of those whose parents cannot afford to opt out of the state system? Abbott professes to believe in an egalitarian society, but by buying her son’s education, she ultimately helps to entrench the divide in our society between the haves and the have-nots – of whatever race.