New guidelines are being drawn up to help colleges cope with the confusion over cannabis legislation following the declassification of the drug this week.
The Department of Education and Skills has asked drugs awareness charity DrugScope to prepare a briefing paper for futher education colleges.
The paper is expected to advise colleges how to react if students bring drugs onto campus, and how they can play a key role in educating young people about drugs. It will also list agencies colleges can turn to for support on drugs issues.
Concern has been expressed that the reclassification of cannabis from class B to the less serious class C, which took effect yesterday, will give younger students the message that cannabis is no longer illegal.
The Home Office has had to launch a pound;1 million advertising campaign advising that possession of cannabis is still a criminal offence, though the maximum penalty for possession has been reduced from five to two years.
According to David Blunkett, the Home Secretary, more than 40 per cent of people under 30 have smoked cannabis.
Natfhe, the lecturers' union, said: "Open use of these substances is still prevented by the declassification. It will allow use of cannabis in the home, but I suppose it will increase the possibility that these substances might be brought onto campus, so clear guidelines and enforcement mechanisms are needed.
"What we would hope to avoid is lecturers being used as classroom police.
That is not their role, and it could undermine the student-teacher relationship.
"It is the role of the individual institution, in terms of support and discipline, to take action. Institutions should begin to prepare themselves."
Hajra Mir, of DrugScope, is playing a key role in the production of the briefing for colleges, which will be published next month. She said that while drugs education was part of the school curriculum, there was no onus on colleges to give out drugs information to their young people.
"The briefing paper identifies the challenges for colleges," she added.
"Colleges are dealing with an age group where drugs use is quite high.
Young people need accurate and up-to-date information. Tutors have so much on their plates so it is making sure they have access to other services and advice to call on for advice and support on drugs issues."
Even before the reclassification of cannabis, many students believed that use of the drug was not an arrestable offence, she said.
One survey found that 48 per cent of students believe cannabis possession would be ignored by the police, 45 per cent believe they would escape with a police warning, and only 8 per cent believed they would be prosecuted.
Ms Mir added: "Colleges tend to focus on incident management, not on the drugs education issues. We want to stress the importance for colleges to have a drugs policy in place. Some might just stick up posters around the place and that's their drugs education.
"It should be focusing on giving young people the opportunity to explore attitudes to drugs. Good practice on drugs is not just about knowledge, it is about what to do in certain situations."
The advice from the Association of Colleges is that it is up to individual colleges to develop their own policy on drugs issues.
Ruth Silver, principal at Lewisham College in south east London, said her strict line on drugs would not change: "Drugs and learning don't mix.
Lewisham College has a zero-tolerance approach to drugs and smoking is not allowed on campus. The declassification of cannabis will have no impact on the college's strict ban on drugs,"