A radical overhaul of league tables is needed to ensure schools in deprived areas are treated fairly, an influential committee of MPs said this week.
Parents would be given a far better picture of schools' performance if outside factors such as economic and social deprivation were taken into account, it said.
The report by the public accounts committee follows an inquiry into secondary league tables by the National Audit Office which found that raw exam scores are of "limited value" in judging schools.
The inquiry showed that one in 10 of the secondaries in the bottom 20 per cent using raw scores would be in the top 20 per cent if external factors had been considered.
Ministers have repeatedly said that poverty is "no excuse" for poor exam results.
Edward Leigh, Conservative MP for Gainsborough and chairman of the PAC, said: "Taking into account external influences outside schools' control can have a dramatic effect on performance.
"This enhanced information must be available to parents so that they can take it into account in selecting schools."
Changes should be made in time for the publication of performance tables next year and the Office for Standards in Education should include both raw and adjusted scores in inspection reports.