The number of super-sized schools with more than 1,500 pupils has shot up in the last decade, leading a campaign group to warn that pupils’ behaviour will deteriorate.

The charity Human Scale Education has obtained figures from the Department for Education and Skills showing that the number of schools with between 1,500 and 2,000 pupils increased by 123 per cent since 1995, from 114 to 258.

The charity believes that enthusiasm for expanding successful schools flies in the face of parents’ desire for smaller establishments. It fears that larger schools overwhelm some pupils, contributing to poor behaviour and high drop-out rates. It is urging Alan Johnson, Education Secretary, to commission research into its concerns.

The DfES figures show the number of secondary schools with between 1,000 and 1,499 pupils has also increased since 1995, from 943 to 1,276. During the same period, the number of schools with fewer than 500 pupils plunged from 276 to 156.

Mary Tasker, chairwoman of Human Scale Education, said children in large schools risked becoming “cogs in machines”.

Ms Tasker wrote: “Human Scale Education is calling upon the Government to look again at the relationship between secondary school size and pupils’

learning. It is now well documented that smaller schools and small learning communities created within large schools, can generate the kind of personal relationships and positive attitudes towards learning that can bring about dramatic improvements in young people’s achievements.”

The group, with the Gulbenkian Foundation and supported by the Esmee Fairbairn and Paul Hamlyn Foundations, is giving grants to 50 secondary schools which want to develop smaller units for groups of pupils. So far, 10 schools have participated.

The charity believes Building Schools for the Future, which aims to rebuild or refurbish all secondary schools within the next 14 years, has contributed to the trend towards bigger schools.

The 1,000-pupil Wilsthorpe Business and Enterprise college in Derbyshire has received HSE funding, and proposes forming a Year 7 mini-school for the September 2007 intake. Children will be taught by no more than six teachers, centred in one area of the school. Other schools taking part in the scheme include Allerton Grange school in Leeds, which has 1,800 pupils, and Glossdale community college in Derbyshire.