A SURVEY commissioned by the UK's leading independent road safety charity, IAM RoadSmart, has revealed that the majority of motorists are unaware of the amount of alcohol that will tip them over the limit.

Moreover, half of the motorists in the study admitted they are prepared to drive the morning after festive drinks or their Christmas party.

Of more than 1,000 motorists surveyed, 50 per cent said they were likely to get behind the wheel the next morning following festive drinks, even though it takes many hours before large amounts of alcohol leave the blood stream.

Worryingly, when respondents were asked how many micrograms of alcohol are permitted in 100 millilitres of breath before they would fail a police breathalyser, on average, the answer was 52. This is despite the fact the actual threshold is only 35 micrograms per 100 millilitres of breath.

These admissions have led to IAM RoadSmart to call for drivers to take more responsibility this festive period and be extra careful.

Neil Greig, director of policy and research at IAM RoadSmart, said: "Drinking and driving simply does not mix and every driver should plan to leave the keys at home rather than face a fine, lengthy ban or time in a police cell.

"Worryingly, the research also highlights that there is still real ignorance regarding how much alcohol is enough before it is illegal to drive. Although motorists may well think they know how many drinks will typically tip them over the limit, individual characteristics such as body weight, food consumption, gender and metabolism will also determine the reading.

"So, if you're planning to drink alcohol at a Christmas celebration, do not try to calculate whether or not you are over the limit. It is always best to make it none for the road."

The charity has also reiterated its plea to the government to roll out a smarter package of longer-term measures to help drive down the number of drink drivers on Britain's roads into the new year.

This includes a lower drink-drive limit to reinforce goodbehaviour, fast-track ofevidential roadside testing machines to release police resources and tailored approaches to help drivers with alcohol problems.

Mr Greig warned: "A prosecution for drink driving this month will not only ruin your Christmas but also impact the rest of your life through public humiliation, loss of job, family break up and a criminal record. We estimate that last drink that takes you over the limit could cost you up to £70,000. If that isn't a sobering thought then nothing is."