Music classes should debate the meaning of the Beatles song “Lucy in the Sky with Diamonds“tse while maths teachers set questions on the street prices of crack, if schools follow new guidance from the Government on drugs education.

The booklet, which will be sent to schools next month, suggests that heads should consider taking a cross-curricular approach to the illegal substances instead of only teaching them in personal, social and health education classes.

The Department for Education and Skills suggests that geography lessons could explore the “economic activity” relating to the drugs trade while religious education could examine related issues of “morals, values and cultural diversity”.

Music and art teachers could also contribute to pupils’ drug education by “exploring popular culture” and perhaps discussing whether the Lucy in the Sky refers to LSD. Other subjects which the DfES suggests could help include English, drama, physical education, science and computer technology.

The new drugs guidance was the subject of controversy this week after Prime Minister Tony Blair said in an interview with the News of the World that it would empower heads to carry out random drugs tests and organise sniffer dog sweeps of their schools.

He added that, although he could not force schools to carry out random tests, he supported them and so would local communities. His comments have dismayed DfES officials who say the remarks are misleading.

The guidance, which has already been published on the department’s website, makes no direct reference to “random” testing. Instead it acknowledges that some schools are already using sniffer dogs and drug testing in certain situations. Rather than promoting these approaches, it urges schools to take extreme caution.

Heads are told that they must consider whether such methods are an effective use of school resources, whether they are culturally insensitive to pupils, and if they are “consistent with the pastoral responsibility of the school to create a supportive environment”.

The guidance also urges teachers to stress to pupils that cannabis remains illegal and potentially damaging to their health, in spite of the Government’s decision to downgrade its classification.

David Hart, general secretary of the National Association of Head Teachers, said the state schools he knew which had tried drug-testing had used it on selected students, rather than randomly. “Drug testing is a useful additional weapon for schools, but I don’t think headteachers want pupils randomly tested as if they were entering a professional sports contest,” he said.

John Dunford, general secretary of the Secondary Heads Association, said that it was perfectly sensible for teachers to raise drug-related issues across the currriculum.

“If a teacher is doing a lesson on the geography of South America then he should bring up the subject of the drugs trade,” he said.

Drugs: guidance for schools is at www.dfes.gov.ukdrugsguidance