ONE-THIRD of Scots drivers do not know how much alcohol they are legally allowed to consume before they drive, a survey has found.

Almost one in five Scots admit to driving the day after a night out over the festive season while being unsure if their blood alcohol level is within safe limits, and 4% admit to not being able to remember their journey home because they had had so much to drink before getting behind the wheel.

The figures, compiled from research by the Post Office, come as the latest drink-drive campaign by the Scottish Government urges motorists to shun alcohol completely before driving.

Anyone caught driving with a blood alcohol level exceeding 80mg/100ml - equivalent to 35mg alcohol in 100ml of breath - or more will face arrest. Although it is roughly equivalent to one-and-a-half glasses of wine or one-and-a-half to two pints of beer, it is impossible to say exactly how many drinks or units is safe because each person metabolises alcohol differently.

Paul Havenhand, head of insurance at Post Office, said: "Christmas is a time when many of us are likely to have an extra drink or two. However, getting behind the wheel when your reactions might be impaired is both dangerous and, dependent upon the amount you have had, illegal."