New Department for Education and Employment advice on school buildings standards next month will raise the issue of privacy in changing rooms.

It asks schools to consider balancing the need for supervision against modern expectations and religious requirements.

The DFEE circular, which accompanies revised regulations, gives a strong hint that new building plans will need to meet these expectations. But the rules stop short of requiring schools to convert communal showers which would impose a huge bill for many schools. Council architects have in the past provided separate showers only for girls.

Michael Marland, the London head who first drew attention to the issue, says that the former Inner London Education Authority and its London County Council predecessor felt that, while the girls had to be spared maidenly blushes, it did boys good to bounce around starkers.

But it was the threat of legal action by the father of a Muslim pupil at his Westminster school that pushed Mr Marland into action. Islamic law requires that, after puberty, neither boys nor girls should see each other’s private parts. They are supposed to avert their gaze from nudity.

Mr Marland persuaded the DFEE to fund the conversion of the showers at his 2,000-pupil school, North Westminster, and then to embark on a two-year consultation with religious groups and educational organisations.

Most of Britain’s leading public schools have now abandoned or are in the process of replacing the communal “run-through” showers, which state schools have used as a model.

Mr Marland’s own old school, Christ’s Hospital, which is about to spend about pound;95 million on improved facilities for boys, says it will incorporate cubicles for boys as well as girls.

Rugby is going over to separate showers. And Mr John Lewis, Eton’s head, says that the school has long provided shower cubicles with curtains or doors.