Linda Croxford, senior research fellow at the Centre for Educational Sociology at Edinburgh University, last week told a conference on measuring inequalities in education: “The most significant factor in determining pupils’ attainment is their mother’s education but I do not know of any single local authority that collects this kind of data.”

It was important to measure differences between pupils, classes and schools and address persistent inequalities but current data and methods of collecting it were inadequate, Dr Croxford told the conference at Edinburgh University. Results from 5-14 tests were unreliable and self-evaluation measures were at times not much better.

Evidence from school-leaver surveys showed that attainment at Standard grade and Higher and entry to university depend on social class, gender, family size and structure, local area deprivation and the intake of schools.

She sometimes had to agree with the old maxim that the purpose of education was to allow middle-class pupils to take up jobs in the professions and the unskilled to go into manual jobs. Class was still the strongest factor in determining chances at school and beyond.

Dr Croxford pointed to particular gaps at Standard grade where in 1998 there was a 43 per cent difference in Credit level awards between students of professional parents and unskilled manual parents. Differences between girls and boys accounted for only an 11 per cent gap in performance.

More than 70 per cent of pupils from a professional background went on to university against 11 per cent from unskilled families and all the evidence showed that inequalities were reinforced during the school years.

Alan Bell, of Edinburgh University’s Centre for Education for Racial Equality, said ethnicity was one neglected factor that can affect performance, although that would be partly rectified later this year when information emerges from the ScotXed national and ethnic data collection exercise.

Mr Bell, however, said that there were problems with the questions which were used. “If you were not white and British, what would you tick? Would you tick asylum-seeker or refugee?” he asked.

Studies south of the border continued to highlight gross inequalities which were exacerbated by schools. In one unnamed local authority in 1998, baseline testing on entry to primary school showed that black Caribbean and African students topped the ability list by a wide margin.

Eleven years later at GCSE level, they propped up the ethnic league table, coming well behind Indians and whites. They were outperformed by Pakistani and Bangladeshi students, but not by the same differences.

Mr Bell said that Indian pupils invariably came out top of the performance tables. “Roughly 90 per cent of the British Asian population retain a significant proportion of their language, therefore English as an additional language is not the barrier it is sometimes made out to be,” he said.