The Secondary Heads Association (SHA) called for action to stop drama being squeezed out of schools by the national curriculum.
Peter Miller, the association's former president, said drama should be a compulsory part of all children's education, and called on the Teacher Training Agency to make drama part of all teacher-training courses.
The union wants the Government to force schools to set aside time for drama when ministers review the national curriculum in 2000. Mr Miller, headteacher of Wrenn School, Wellingborough, said: "There are a lot of children who are not getting this essential and valuable experience, and that really concerns us. A school without drama is a school without a soul."
The actor Sir Derek Jacobi, speaking at the launch of the SHA book Drama Sets You Free, added his weight to calls for more drama in schools. He said: "I would not have become a professional actor if it had not been for my school and the influence of my teachers.
"I was in an all-boys school, which did not have drama as part of the curriculum, but we had a flourishing dramatic society. I had a very privileged school life. I loved school and I acted all the time."
The SHA surveyed drama lessons in 700 schools. It found that nearly a third of drama teachers had no specific training in the subject. Some 15 per cent of schools had no drama department, and nearly a quarter had no head of drama.
But the survey also found that drama thrived as an out-of-school activity. Only 5 per cent of schools did not offer some form of drama outside normal lessons. Mr Miller said drama was "noticeably less secure" in all-male schools than in their co-educational counterparts, and that it was often simply incorporated into English lessons.Reuse content