LEADING road-safety campaigners have urged police and prosecutors to hit with softer penalties some motorists breaking Scotland's new drink-drive limits.

The Royal Society for the Prevention of Accidents has advised Scottish government ministers to apply a lesser ­sanction against those above the new limit but still below the outgoing threshold.

The organisation said it was calling for even temporary reduced penalties because "it does take time to change people's attitudes".

At the weekend, leading health experts and trade organisations warned morning-after motorists could be hit by the lower limits, which will be in place before the end of the year.

Ministers announced last week that the drink-drive limit would fall in December from 80mg per 100ml of blood to 50mg.

It means drivers who have consumed half a pint of strong beer or a glass of wine could fall foul of the law.

Concerns have been raised about people crossing the Border and being over the limit, despite being still legal if coming from England where it will remain 80mg, as well as criminalising motorists who may have been drinking the night before.

The Scottish government said it does not have the power to vary the penalties for drink-driving as these are reserved for Westminster. It will launch a series of television advertisements ahead of the introduction of the new limit, including channels around the north of England to target drivers who cross the Border regularly.

But in its submission to the Scottish government on the changes, Rospa said: "To encourage public acceptance of the new limits, Rospa would support a six-month rather than 12-month disqualification for drivers between 50mg and 80mg/100ml.

"This would recognise that some people may inadvertently exceed the new lower limit but recognise the seriousness of the offence, and a six-month disqualification would still be a significant deterrent for most people.

"The penalty for those exceeding 80mg should continue to include a driving disqualification for at least one year, and longer for higher levels of alcohol."

At the weekend, Paul Waterson, chief executive of the Scottish Licensed Trade Association, questioned whether being just over the 50mg level would carry the same sanction as those currently in excess of the current legal limit.

He said in some European countries where 50mg is the limit the sanctions are less severe.

Karen McDonald, head of Rospa Scotland, said: "In the early days of the introduction we are endeavouring to provide an alternative aspect for consideration. We are saying they should be penalised but perhaps we recognise that it does take time to change people's attitudes."