The West Yorkshire district has traditionally had between 10 and 20 secondary schools with rolls of well over 1,000 pupils.

But when the authority decided to undertake a massive re-organisation from a three to two-tier system in 2000, pupil numbers per school shot up overnight.

Rolls of many of the district’s upper schools for 13 to 18-year-olds rose to nearly 2,000 as they expanded to accommodate middle school pupils and an 11 to 18 intake.

Local teaching union representatives warned the policy was a mistake. They said that rolls of more than 1,300 were already causing problems and that increasing them would make things worse.

Stuart Herdson, the Association of Teachers and Lecturers’ Bradford secretary, argues that huge schools create a critical mass of pupils with behaviour problems, who draw in others who would otherwise remain on the fringes.

“Before you know it you have got more than 100 very difficult pupils,” he said. “But in a small school that just wouldn’t happen.

“In small schools children with behaviour problems get individual attention but in big schools they get lost.”

The policy also went against prevailing wisdom in the US where the trend since the 1990s has been to carve up sprawling state school campuses into smaller “learning communities” or “multiplex schools” of no more than 400 pupils at primary level and 800 at secondary.

Some 130 of Chicago’s 650 state schools are now small and New York plans to open 200 small schools in the next two years. But Bradford went ahead with its plan and by September 2002 it had no fewer than seven schools with between 1,700 and 2,000 pupils.

One of them, Rhodesway, had gone into serious weaknesses the previous year and Bob O’Hagan, its new head, decided that size was the problem.

Pupils had told him that they felt lost in Rhodesway after moving from middle schools. They felt they were “just a number” and did not have the sense of anyone in the school looking out for them.

His solution was to divide the school into three separate entities - a sixth-form centre and two distinct 11 to 16 schools: Rhodesway Sharman and Rhodesway Bennett, specialising in sciences and the arts respectively.

The experiment did not have long to work before December 2002 when the school was placed in special measures and Mr O’Hagan left.

Ian Cox, his successor, intends to look at the structure again because, he said, inspectors had raised the issue of consistency between the different schools.

Numbers at Rhodesway have since fallen from 1,800 in 2001 to a slightly more manageable 1,450. But Mr Cox says that even if Rhodesway reverts to a single school something will have to be done to break it down from a monolithic structure into smaller units.