MOTORISTS in Scotland are to face tougher drink-driving laws that will put some over the legal threshold after just one glass of wine.

The stricter limits in Scotland could be in place next year after Justice Secretary Kenny MacAskill said yesterday proposals to implement a limit of 50mg of alcohol per 100ml of blood in place of the current 80mg would be published later this year and made law "as soon as possible".

The change would mean that some people who get behind the wheel after drinking a single pint of strong lager could face a mandatory 12-month driving ban and will put Scotland at odds with England and Wales, where an independent report recommending a lower limit was thrown out by the Transport Secretary last year.

Motoring organisations have welcomed the proposals – which will bring Scotland into line with France, Germany and Spain – but warned that the Scottish Government would have to ensure the new limit is properly enforced and confusion among drivers avoided.

Power over setting drink-driving limits was devolved as part of the 2012 Scotland Act, which recently received royal assent.

In response to a call by the Liberal Democrat leader, Willie Rennie, to enact the powers as soon as possible, Mr MacAskill said: "The Scottish Government has long called for a reduction in the drink-driving limit to 50mg. We strongly believe that reducing the drink-driving limit will save lives, and evidence from across Europe shows that alcohol-related road deaths drop dramatically where the limit has been reduced.

"Having secured the powers to take this forward through the Scotland Bill, the Scottish Government as a priority will bring forward proposals later this year, with a view to the change taking effect as soon as possible."

A Government source said the plans would be put out to consultation later this year and would then either be drafted as an isolated bill or incorporated into other legislation.

He dismissed fears that having different laws either side of the Border would create confusion among motorists.

"These are the same arguments we've heard in relation to free personal care for the elderly, the smoking ban and minimum alcohol pricing. Westminster is perfectly free to follow Scotland's example on these issues," the source said.

Andrew Howard, spokesman for the Automobile Association, welcomed yesterday's announcement, pointing to a survey which found that 66% of its members favoured the lower limit, but warned that more roadside policing would be needed to enforce the new limit.

"Though the AA has supported a lower limit we didn't make too much fuss when the Coalition knocked it back because, with all the funding cutbacks, we wondered where the money would come from and whether the law would fall into disrepute if they didn't enforce the lower limit," he said.

Mr Howard said clear signs would need to be put up at the Border advising English motorists of the lower limit.

Neil Greig, director of the Institute of Advanced Motorists, has warned that a lower limit could risk undermining the public's understanding of drink-driving laws, which are based on severe punishment at a relatively high alcohol threshold.

Sentencing rules currently stipulate a 12-month driving ban for anyone caught over the legal limit, barring exceptional circumstances, fines of up to £5000, or a maximum six-month jail term.

Sarah Fatica, general manager at Brake, the road safety charity, said: "We're pleased that the Scottish Government is taking heed of the warning that road safety charities and the EU are sending out about the current drink-driving limit.

"It's certainly a step in the right direction and one that we commend, and we would like to see the British Government also lowering the drink-driving limit."

However, Ms Fatica said she would ultimately welcome a limit of 20mg or less, saying the "best message" to send out was one of zero tolerance for drink-driving.

Yesterday's announcement received broad political support, including from the Conservatives, who opposed the lower alcohol limit south of the Border.