The claims came from Stephen J Ball in his inaugural lecture as Karl Mannheim professor of sociology of education at London University's Institute of Education.
He also said setting and streaming of pupils is now widespread, not because of its educational value but because it allows well-off parents to separate their children from "others" whom they consider socially and intellectually inferior.
It is also politically attractive, he said. Tony Blair had become the leading advocate of ability grouping because he knew the policy would win him middle-class votes.
Professor Ball said: "It is extraordinary and saddening that at a time when evidence-informed policy and practice is very much the vogue, that we are witnessing a wholesale return to the social barbarism of setting by ability."
He went on to argue: "Middle-class parents see setting as a way of insulating their child from untoward influences: 'other' children who are seen as disruptive or work-shy or simply less able."
Yet the overwhelming research evidence showed that grouping by ability was educationally damaging and led to greater inequalities between children. He said studies showed that pupils in the bottom sets lost out - they were taught by the youngest and least experienced teachers, with the highest rates of staff turnover. There was less interaction between these pupils than in the higher sets.
Pupils in lower sets also had low self-esteem and were more likely to be alienated from school, disruptive or apathetic. This "demeaning and dispiriting" experience could affect them for the rest of their lives, he said.
Professor Ball added that the emphasis since the 1980s on greater parental choice had given the middle classes greater power to push for the rights of their own children at the expense of the system overall.
Labour has enthusiastically backed setting in primary schools. Its 1997 White Paper reinforced advice issued by the Conservatives in 1993 that schools should introduce more setting by ability.
But research published last month indicated that primary schools are resisting this pressure as evidence showed that most still teach pupils in classes or mixed-ability groups, rather than in ability-based sets.