A health expert has warned motorists that a full Scottish breakfast and coffee will not prevent them from being over the drink driving limit the morning after the night before.
Dr Peter Rice, chairman of the Scottish Health Action on Alcohol Problems, said limited sleep, a shower and exercise would not help speed up the process of ridding the body of alcohol.
He told Holyrood’s justice committee that “time” was the only solution and a person who drank half a bottle of wine at 8pm would not be clear until 2am.
But Chief Superintendent Iain Murray, head of roads policing at Police Scotland, went further and said people should not drink a drop if they were driving the next day.
The men spoke out after MSPs questioned them on how people were supposed to know when it was safe to get behind the wheel under the new drink drive limit which is being cut from 80mg in every 100ml of blood to 50mg from December 5.
Dr Rice said: “If you have a half bottle of wine with a meal and start to drink at 8pm, then your blood alcohol would be getting to zero at about 2am.
“If you drink more heavily than that your metabolism of alcohol does not speed up, it is like a shop with one check-out, you can only go at one speed.
“Nothing speeds that up – coffee, sleep, shower, exercise, full Scottish breakfast – none of that makes any difference.
“Time is the only thing that clears alcohol from the system.”
Dr Rice said drinking heavily the night before driving was a “risky thing to be doing”.
Mr Murray said: “If you are going to be driving in the morning, do not drink the night before.
“The simple message is don’t risk it. It is not just a legal limit, the fact is your ability to drive is impaired potentially.”
Mr Murray said the police would not be setting up road checks outside housing estates to catch people and would only pull motorists over if they drew attention to themselves.
Margaret Dekker, of Scotland’s Campaign against Irresponsible Drivers, said people must take “responsibility” for their actions and home breathalyser kits were available to buy.
Committee convener Christine Grahame said the public would benefit from guidance on the issue so they do not unwittingly break the law.