They range from midday supervisors and catering staff to bursars and business managers, teaching assistants and learning mentors. And their qualifications vary enormously.

Some are graduates, even qualified teachers but the Government’s own Labour Force survey suggests the median among the 200,000-plus support staff is NVQ level 2 or equivalent, the top grade GCSE.

Inspectors believe they make a difference, particularly in literacy and numeracy - even though they make work for teachers in planning and preparation. “Observable gains in a pupil’s learning often result from the individual attention of the teaching assistant in a particular lesson,” said the Office for Standards in Education last year. But then chief inspector Mike Tomlinson said: “As yet, the considerable public investment in expanding their (assistants’) numbers has not led to a reduction in teachers’ workloads.”

But even the National Union of Teachers, the classroom union most hostile to the government plans, appears convinced of their worth. A survey in April showed 58 per cent of members agreed they had cut workload.

But research suggests heads feel re-allocating administrative duties has little impact on pupils. A survey of 14,000 primaries discovered that schools with relatively high levels of admin support tended to be doing slightly worse than expected.

There will be three career routes for support staff: pedagogical - eg a technician, music specialist or teaching assistant; behaviour and guidance - eg mentors or staff involved in pastoral care; and admininstration, including school administrators or premises managers. Standards and training for higher-level assistants will be developed by 2004.

Qualified teachers will have overall responsibility for teaching and learning but assistants will be able to do some teaching under supervision and cover for short-term teacher absences.