full-service extended schools can have “life-changing” effects on their pupils, researchers have found. But there was no evidence, said the three-year evaluation, that attending one helps most pupils to do better in their exams.

The Government has taken the evaluation as an endorsement of its decision to introduce a limited version of the initiative, started in 2003, to every school by 2010. Alan Dyson, an education professor at Manchester university and co-author of the report, said: “We’ve been struggling in this country to reach those children in greatest difficulty. What we think we’ve got here is an approach that makes a real difference to them.”

Full-service extended schools provide access to health services, adult learning, community activities, study support and 8am-to- 6pm childcare.

The report said they were a good investment.

An internal Department for Education and Skills analysis, seen by the evaluation team, said that progress in such schools was roughly double the national average, with the number of pupils getting five good GCSEs increasing by 5 per cent, compared with 2.5 per cent nationally.

Professor Dyson said: “There’s no contradiction between DfES’s finding that FSESs were improving rapidly and our finding. One explanation might simply be that FSESs, serving some of the most disadvantaged populations in the country, started from a long way back. So they were able to improve rapidly without necessarily catapulting the majority of their pupils ahead of their peers elsewhere.”

The average annual cost of running a full-service school ranged from pound;391 to pound;1,961 per pupil. But taking into account the gains to the economy from improved results, the benefits outweighed costs by between pound;790,000 and pound;4.5 million.

One in eight schools offer some form of extended service, according to official figures. One is South Chadderton school in Oldham. Its head, Chris Hill, said: “It has had a massive positive effect. We were under notice to improve and we are now not. We have the additional resources in order to focus on those things about school that students find most difficult.”