The study, carried out for the Child Poverty Action Group by researchers at Oxford University, paints a picture of a divided school system with the middle classes widening the educational gap between themselves and the less privileged.
Better-off pupils are increasingly congregating in the same schools, leaving other schools with a disproportionate number of poor and difficult pupils. Between 1988 and 1996 the proportion of pupils in poorer areas gaining five or more A-C grades rose from 20 to 32 per cent.
However, there was an even bigger increase - from 30 to 48 per cent - in those in the most affluent local authorities reaching the same standard.
Though the number of 17-year-olds in full-time education has risen everywhere, it has gone up by 27 per cent in places with the most professional families but only 18 per cent in the most working-class areas.
The researchers say: "Individual school results suggest that in some areas there are schools with increasing proportions of socially disadvantaged pupils, some of whom have been excluded by other schools. Such schools may find themselves trapped in a vicious circule, with the local authority having limited capacity to help."
Yet the poorest councils are not getting their fair share of resources, the study suggests.
The additional needs formula used by the Government to help the least prosperous local authorities benefits Harrow more than Barnsley in Yorkshire and Westminister in London more than Birmingham or Liverpool. Most failing schools are found in the poorest areas.
The proportion of poor pupils has risen: just under 17 per cent were receiving free school meals in comparison with 11 per cent four years earlier.
Spending on schools has grown since the mid-70s by about 14 per cent in real terms but as a proportion of GDP spending is down over the same period from 3.7 per cent to just over 3 per cent.
Though spending per pupil rose quite sharply until 1990, since then it has been falling. In secondary schools it has now returned to the level it was in the mid-eighties. Spending on buildings is running at less than half the level of the mid-seventies.
Educational opportunities and results have become more unequal during the eighties and nineties, the study says.
"It is too early to say authoritatively how far recent policies have contributed to these divisions, but the idea of a market seems likely to lead in this direction particularly when it is allied to a tough squeeze on overall resources."
Both schools and society have become more fragmented with growing proportions of families with children concentrated in particular urban areas, according to the Oxford researchers.
Britain divided: the growth of social exclusion in the 1980s and 1990s edited by Alan Walker and Carol Walker. Child Poverty Action Group, price pounds 9.95.Reuse content