Diane Abbott, the maverick Labour MP who horrified her fellow leftwingers in the party by sending her son to a private school, has enrolled him in a sixth form in Ghana so he can “get in touch” with his African roots.

James Thompson, 17, her son from a brief marriage to a Ghanaian architect, has been studying for an international baccalaureate and helping African orphans to read and write.

Abbott, 55, the Cambridge-educated daughter of Jamaican immigrants, became Britain’s first black woman MP when she was elected to the Hackney North and Stoke Newington seat in north London in 1987.

She established a reputation for opposing privilege but was accused of hypocrisy in 2003 for enrolling James, then 12, into the City of London school rather than an inner-city comprehensive.

She had previously criticised Tony Blair for sending his sons to the opted-out London Oratory school and Harriet Harman for choosing a grammar school outside her constituency for her children.

Abbott admitted her decision was “indefensible” but went on to explain it in an interview with a newspaper, for which she was reportedly paid a sum equivalent to a term’s fees. She said she had to weigh her political reputation against her son’s best interests “and I chose my son”.

She added that her decision was not unrelated to gun crimes in her constituency.

James prospered at the school, whose alumni include Herbert Asquith, Kingsley Amis and Daniel Radcliffe, the Harry Potter actor, and achieved 11 A*-grade GCSEs.

Abbott travelled to Ghana to visit the Hermann Gmeiner International College at Tema — named after an Austrian philanthropist who set up SOS Children’s Villages for abandoned and orphaned children after the second world war.

She pays £3,000 a year in tuition fees plus £2,400 for her son’s board.

James’s campus adjoins the Ghanaian branch of the charity and he has agreed to do 150 hours of “community service” helping its orphans as part of his two-year course.

Titi Ofei, the principal of the college, said: “His mother wanted him to get in touch with his African roots.”

Abbott declined to discuss her son’s progress: “It is bad enough being a politician’s child at the best of times.

But the tidal wave of press criticism and comment about my choice of secondary school was not a pleasant experience for my son. For that reason, I avoid talking or writing about him now.”