The move comes a year after the RAC mounted a campaign to give drug driving the same focus as drink driving. Fox accuses the Government of failing to tackle the problem of drugs - including antihistamine treatments for hay fever - which impair driving ability.
'The Secretary of State for Health has passed the buck to the Department of the Environment, Transport and the Regions,' he said. 'Meanwhile millions of motorists are putting their lives and the lives of others at risk.'
The DETR declined to comment, but a spokesman for the Proprietory Association of Great Britain (PAGB), the trade body representing manufacturers of over-the-counter medicines, said few products for allergies contained sedatives and those that did carried clear and unambiguous warnings on the packs, with recommendations not to drive.