Indeed, this government is anxious to improve the reporting of information about exclusions generally, and says the present picture is "patchy".

How many pupils are excluded over drugs?

The government's Social Exclusion Unit says a recent independent survey of a sample of local education authorities suggests there may have been about 12,700 exclusions in England for all reasons in 1996-97.

There is no breakdown of the reasons. But research on figures from one large local authority suggest that those excluded for drugs matters - which included smoking, alcohol and cannabis offences - were 4% of the total, which might translate to something like 500 children across the country.

The vast majority of exclusions are for bullying, assaults, disruptive behaviour and verbal abuse.

What happens to children who are excluded?

Local education authorities have a duty to see that children who are permanently excluded should be quickly reintegrated back into school wherever possible. But this happens in only about a third of cases.

The rest receive what is known legally as 'education otherwise'. This is either in special centres known as pupil referral units, through home tuition - which may only be for a few hours per week - or in a further education college.

Current government guidance recommends that teachers set work for children who are excluded for a fixed term. But the guidance is not statutory and it seems this rarely happens.

There are about 25,000 children receiving this sort of education.

A report by the Office for Standards in Education on pupil referral units said that more recently they were becoming more successful in improving attendance and stimulating positive attitudes to learning and behaviour.

In his speech to the Labour Party Conference last month, the Education Secretary, David Blunkett, announced new money to try to tackle exclusions - including the idea of 'dowries' for schools that accept excluded pupils in an effort to keep them in mainstream schooling.

"Those who are out of school, those who are disaffected, those who are beyond the reach of the classroom are the ones who get least qualifications, are most likely to be unemployed and who tragically are most likely to be in trouble with the law," he said.