The Children’s Food Campaign, the National Union of Teachers and the Design and Technology Association (DTA) are among those who have called for cookery to be mandatory for all secondary pupils.

Eighteen months ago, Ruth Kelly, then education secretary, appeared to endorse all children being taught practical cookery.

But her successor, Alan Johnson, watered down the pledge to a voluntary entitlement for pupils, whereby those who asked to study the subject had to be offered it. But he promised that all pupils would be given the chance to receive 24 hours of cookery tuition if they asked for it.

However, under changes planned for the curriculum for 11 to 14-year-olds, food technology would become one of four design and technology courses, from which schools would only have to offer three. This leaves open the possibility that they would choose not to offer cookery.

Figures from the DTA suggest that in 2000, some 5 per cent of schools lacked food technology rooms or qualified staff. Since then, the figure has gone up to 15 per cent.

The campaigners acknowledged that the proposed changes, to be introduced next year, were an improvement on current provision. Many pupils are not now taught practical cookery. But they said they did not go far enough.

Richard Watts, Children’s Food Campaign co-ordinator, said: “The problem with voluntary cooking lessons is that they are only going to be taken by children who are already likely to have cooking skills.

“Unless we make kids learn to cook, we are not going to get to the hardcore of pupils who currently miss out and we are setting up new problems for the future.”

A Department for Education and Skills spokesman said: “Every key stage 3 pupil who wishes to take cookery lessons will be entitled to do so. We will not enter into a debate on semantics.”