The government has delivered new guidance to headteachers on tackling drug misuse in their schools.

It follows an interview with the prime minister in which he gave his backing to random drug testing of pupils.

An ICM poll for the newspaper found that 82 per cent of parents and 66 per cent of children supported such a move.

However, the proposal was only included as "an option" in Tuesday's memorandum.

Headteachers have been encouraged to use "one strike" to permanently exclude any pupil found dealing drugs on school premises.

Zero tolerance

And every school has been told to write their own drugs policy, while teachers should aim to identify those students considered vulnerable to drugs misuse and ensure they receive the appropriate support.

All staff should also be given drugs awareness training, the Department for Education and Skills added.

"We are committed to a zero tolerance policy towards drugs in schools, and many schools are already doing excellent work on drug education," said schools minister Stephen Twigg.

"Nearly all schools now have drug policies, and Ofsted tells us that the quality and quantity of drug education has never been better.

"We believe that headteachers should have every tool in the box when it comes to drug education and prevention, and the guidance issued today gives clear advice on the best ways to deal with any issue around drugs."