As many as one million motorists have driven while under the influence of drugs, a survey has revealed.
Even more drivers appear to have no objection if a close friend intends to drive while high on illegal substances, according to the poll by road safety charity Brake.
About three per cent of motorists admitted to drug driving at least once in the last 12 months.
However, 11 per cent of passengers thought they may have travelled in car with a driver who was high, the survey from Brake and Direct Line Insurance showed.
Based on responses from 1,000 drivers, the survey also showed 29 per cent admitted they would not always speak out to stop a friend driving on drugs.
The survey showed 5 per cent of passengers were unlikely to say something even if their driver was clearly out of control while they were both in the car.
New drug driving regulations are set to be introduced in March next year.
More top news
Rap mogul Marion 'Suge' Knight has been arrested on murder charges after a fatal hit-and-run incident in Los Angeles.
The Canadian used only ice hooks to scale the frozen cliffs, and says the walls were "unstable" and "unpredictable".
Thousands of Virgin Media customers will lose their email address and emails after part of the broadband company was sold to TalkTalk.