The Government’s announcement this week that, if re-elected, it will establish 1,500 “specialist” schools by 2006 offers a golden opportunity to build on the best of our comprehensive system. This should be welcomed by all who work in education. Tony Blair’s blueprint for a post-comprehensive system in which diversity “must become the norm not the exception” is built on growing evidence which suggests specialist schools are outperforming other kinds of state schools - without abandoning their comprehensive roots.

Just last week the chief inspector’s annual report identified 112 particularly successful schools - of which almost 40 per cent were specialist. This follows hard on the heels of the success of the first comprehensive school, Thomas Telford city technology college in Telford, to see all its GCSE pupils achieve at least five A-C grades.

Two pieces of my recent research are relevant here. The first, for the Centre for Performance Evaluation amp; Resource Management at the University of York, found that pupils in selective systems of education do less well than those in comprehensives. The second, for the Technology Colleges Trust, found that specialist schools were more successful than other comprehensives at boosting their pupils’ performance.

There are at present around 600 specialist schools, representing less than one in five of all secondary schools. Evidence of their outstanding performance is accumulating; the chief inspector’s report is simply the latest to capture the headlines. Where did it all start? The first specialist schools (as distinct from 15 city technology colleges) were designated by the previous Conservative government in 1993-94. The criteria included their ability to raise pound;100,000 from business sponsorship (matched by a similar amount from government and used mainly for capital projects) and a competitive bid indicating how they would use additional funding (around pound;120 annually per pupil over a three-year period) to raise standards in maths, science and technology.

Initially only voluntary and grant-maintained schools could apply, and the initiative was actively opposed by many schools and LEAs. However, by 1995 all schools were allowed to bid for specialist status. Later specialisms included language, arts and sports colleges.

Since then, the White Paper Excellence in Schools, published by Labour when it came to office, made clear that specialist schools had a major role to play in developing excellence and diversity in the comprehensive system. It also inssted that specialist schools spend part of their annual grant for the benefit and improvement of neighbouring schools.

The first of these schools have improved their average GCSE outcomes at around twice the rate for all maintained schools; they also show substantially enhanced “value-added” exam performance. Last week’s TES account of Notre Dame school in Sheffield gave a particularly attractive view of the wide range of other ways in which these schools contribute to the personal, social and moral development of their pupils.

My report, Value Added in Specialist Schools, showed that while specialist schools can recruit up to 10 per cent of their pupils by aptitude in their specialism, only about one in 20 does so. Their ability profile remains close to the national average. They also serve a diverse range of social and ethnic communities. One thing, however, which sets them apart is the substantial additional progress which their pupils make compared with their peers elsewhere.

Why are they successful? Obviously extra money helps, but too much can be made of this since, for many schools, it represents a fairly marginal addition of around 5 per cent. What is important is the targeted use to which these resources are put and the unifying sense of purpose in these schools to let nothing stand in the way of improving the educational outcomes of their pupils. Many radical innovations have their roots here - for example technology support for pupils with particular learning difficulties, developing new and challenging vocational courses; extending the school day; and changing the traditional pattern of school terms.

Michael Barber, head of the Department for Education’s standards and effectiveness unit, describes the annual conference of specialist schools as one of the most imaginative and vibrant events he has been privileged to attend.

The emergence of specialist schools has re-invigorated the principle of comprehensive secondary education. Thomas Telford school’s results show clearly that the highest standards can be obtained - for all pupils.

Grammar schools claim to provide the best education - but only for the brightest pupils. In specialist schools we see these standards increasingly being reached by the many. The success of grammar schools has often been at the expense of poorer performance among those not selected. As a nation we cannot afford this waste.

Professor David Jesson is an economist at the Centre for Performance Evaluation, University of York, and co-author, with Sir Cyril Taylor, of “Value Added in Specialist Schools”, published last March by the Technology Colleges Trust.

Will Hutton, 15