Research has shown that more young people now take illicit drugs and drive than those who drink-drive

Edmund King RAC Foundation

But RAC Foundation executive director Edmund King said it would be difficult to set a legal driving limit for cannabis as traces of the drug can stay in the body for up to a month.

As the campaigning arm of the motoring organisation, the RAC Foundation believes the problem of drugs and driving has not been highlighted enough.

Mr King said: "As a first step we would like to see a high-profile television campaign warning of the dangers of drug-driving.

"Research has shown that more young people now take illicit drugs and drive than those who drink-drive."

The government report due to be published is expected to show that the number of road crash fatality victims known to have driven with drugs in their systems has risen from 3% in 1989 to 18% in 1999.

It is considering the introduction of a drug test for motorists which would be similar to a breathalyser.

The government also announced in August that roadside drug tests will be brought in nation-wide following pilot schemes in England, Wales and Scotland.

Prosecution limits

Police can only currently prosecute drivers if they can prove they are incapable of driving because of drugs - something which is difficult to do.

The Transport Research Laboratory in Crowthorne, Berkshire, has recently carried out a study on the effects of cannabis on drivers.

It is also about to begin a study - using volunteers - on how the combination of cannabis and alcohol can effect motorists.

In her speech at the recent Conservative Party conference, Anne Widdecombe proposed a mandatory �100 fine for possessing even the smallest amount of drugs or having them in the bloodstream.

The proposal was quickly condemned not just by drugs workers and rights groups, but by the police and some Tory Party members.