Local authorities are asking for a meeting with ministers to discuss fears that plans to abolish regulations governing the minimum space per pupil in schools could lead to overcrowded classrooms.
The Government is proposing to consult on a revised set of school premises regulations which will dispense with the statutory minimum area standards for teaching and recreation areas.
The announcement last week in a written Commons reply is the culmination of a five-year review of the regulations. It was instigated in an attempt to postpone difficult decisions about the space requirements of the national curriculum, which places greater emphasis on science in primary schools.
In a leaked confidential letter, John Patten, the former Education Secretary, made it clear that the Government faced problems paying for school buildings to be brought in line with regulations.
In his written reply, junior minister Robin Squire said the latest decision had been taken to reduce the regulatory burden on schools. Revising regulations would allow greater flexibility, he said.
However, the Government's new sports initiative appears to have set limits on the extent of the deregulation - minimum area standards are to be retained for playing fields. According to Mr Squire, ministers felt that otherwise there may be a temptation to dispose of playing fields that schools need.
Primary class sizes are rising. School governors warned last week that more than a third of primary schools would have classes of more than 30 children in September. The new rules are expected to come into force in January and the teachers' unions fear they will allow greater cramming of pupils.
Peter Downes, president of the Secondary Heads Association, said the plans could potentially be very bad for children. The Government would not have to provide the capital resources required to make more space available in schools, he said.
The Association of Metropolitan Authorities has asked for a meeting with ministers. Alan Parker, its education secretary, said: "It is vital that we have agreed national standards for teaching accommodation to ensure that all our children receive education in adequate and appropriate buildings."