Teaching assistants could take charge of classes, under radical plans due to be unveiled by Education Secretary Estelle Morris today.

Ms Morris's plans include allowing assistants to take control of classes if work has been set for pupils by qualified teachers. The intention is to allow teachers to concentrate on marking and lesson preparation.

The recruitment of large numbers of classroom helpers will also free teachers of many traditional duties, such as photocopying, collecting dinner money and washing paint pots after art lessons.

Ms Morris will outline her vision for the future of the teaching profession in England and Wales over the next ten years in a speech to the Social Market Foundation in London. A Department for Education and Skills spokesman rejected suggestions that Ms Morris' plans will open the way for staff lacking in qualifications to take charge of classes. Qualified teachers would still have the lead role, he said.

The spokesman said: "We value the role of teaching assistants and classroom assistants. They are not untrained. They are trained, for their support role."

Nigel de Gruchy, general secretary of teaching union NASUWT, said: "We would be prepared to discuss the role of the teacher so we can better focus upon their key professional duties.

"We are certainly happy to develop rules for appropriate support staff, but we can't just push people who are untrained and unqualified into supervising classes."

John Dunford, general secretary of the Secondary Heads Association, said: "Headteachers are already having to use teaching assistants and unqualified staff to take classes in order to cover teacher shortages.

"This is not a long-term solution to the problems of teacher recruitment."