Two senior academics this week urged the Government to acknowledge the need to target extra funding and resources on pupils from disadvantaged backgrounds.
Michael Barber, head of the standards and effectiveness unit at the Department for Education and Employment, is known to believe strongly that poverty is no excuse for low standards of achievement.
However, a paper written by Professor Peter Mortimore, director London University's Institute of Education, and Professor Geoff Whitty, suggests there has to be specific action and extra funding if disadvantaged pupils are not to be left further behind.
The case put by the two professors is that while effective schools do raise achievement, the gap between the advantaged and disadvantaged can only become wider unless special initiatives are targeted at those from impoverished backgrounds. Data collected for ministers by the Qualifications and Curriculum Authority show that schools in advantaged areas on average achieve dramatically better results than their inner-city counterparts which take children from disadvantaged homes.
At its worst, the average score in maths, English and science among 11-year-olds in schools where more than half the pupils are eligible for free school meals is around 40 percentage points lower than the average score in schools where only a handful of children come from disadvantaged homes.
Later this month, schools will be sent a breakdown of last year's national curriculum test results for 11-year-olds. This will show the range of scores achieved by schools in five categories that range from those with fewer than 8 per cent of pupils on free school meals to those with more than half their children on free school meals. An additional category shows the range in schools where more than 50 per cent of pupils speak English as a second language.
However, although the statistics confirm that the highest-scoring schools are likely to be those with the fewest children on free school meals, the most successful schools in disadvantaged areas can outperform some of their counterparts in the leafy suburbs.
The intervention from Professor Mortimore is intended to warn against schools being forced to set unrealistic improvement targets in the absence of extra resources to tackle the specific problems of children from disadvantaged groups.
It says: "What we have been concerned to stress in this paper is that society needs to be clearer about what schools can be expected to do. . . The relationship between individuals, institutions and society is complex and blaming schools for the problems of society is unfair and unproductive.
"Nevertheless, demonstrating that opportunities for some disadvantaged pupils can be changed in particularly effective schools - even if the disadvantaged as a group still remain behind their peers - can itself help to transform a culture of inertia or despair."
Professor Mortimore and Professor Whitty suggest that there is no single strategy that will reverse the long-standing patterns of inequality.
However, they urge ministers to provide extra money to pay for early education programmes for children from disadvantaged backgrounds; provide extra support within school improvement measures for such groups and ensure better co-ordination between the support agencies.
Can School Improvement Overcome the Effects of Disadvantage? by Peter Mortimore and Geoff Whitty is available from the Institute of Education, 20 Bedford Way, WC1H OAL