John Dunford, General Secretary of the Secondary Heads Association, said that headteachers are answerable to too many different authorities, making it more difficult for them to run their schools.

"The accountability of headteachers has reached an unacceptable level and is adding substantially to the difficulties of running their schools," said Mr Dunford.

Dunford: Heads "too acountable"

At present headteachers have to report to a long list of authorities, including school governors, the local education authority, the Department for Education and Employment, the Office for Standards in Education, the Qualifications and Curriculum Authority, Teacher Training Agency and Health and Safety Executive.

Parents also expected headteachers to take responsibility for "all manner of incidents" that were only indirectly connected with school, said Mr Dunford, such as chlidren's behaviour travelling to school, disputes between families and child protection cases.

"Most people have responsibility only for those things over which they have control. For headteachers, responsibilities go much wider than this.

"When issues come to court, the word 'reasonable' is often used to define the extent of legal liability. But it is hardly reasonable for headteachers to be held accountable for so many matters beyond their control."

The worries created by such wide-ranging accountability can lead headteachers to always play safe and to avoid more creative risk-taking, said the union.