SCOTLAND'S tough new drink-drive limit is to have a bigger impact on the future of the pub industry than the smoking ban nine years ago, according to industry experts.

It came as one of the UK's leading brewery and pub chains said the new laws, which cut the safe legal alcohol limit for drivers from 80mg to 50mg for every 100ml of blood, was a 'game changer' for the licensed trade.

It appears many motorists are heeding the advice of police not to drink at all since the laws came into effect on December. Many are also being careful about how much they consume to avoid the "morning-after" effect of still being over the limit.

The number of motorists found to have been drink driving during the festive season dropped by almost a fifth year on year.

But this is impacting on the pub industry, with Belhaven owner Greene King, which has 200 pubs north of the Border, said the introduction of the limit on December 5 had contributed to slower than expected trading.

The company's like-for-like sales in its 1000-outlet retail division rose by only two per cent during the two weeks over Christmas and New Year, compared with 6.4 per cent for the same period in 2013-2014.

Greene King said it was encouraged by its performance in light of the change, although one senior industry figure said the new limit does not augur well for the licensed trade.

Paul Waterson, chief executive of the Scottish Licensed Trade Association, predicted it will have a "bigger effect on the trade than the introduction of the smoking ban" in 2006, which he said hastened the rate of pub closures across the country.

He said people are radically changing their social habits because they fear being over the limit when they step into their cars the next day.

Mr Waterson said: "It's all about the next day. The vast majority of people did not drink and drive if they went out - it's about residual alcohol levels in the bloodstream the next day.

"People are not drinking the night before - they are very concerned there will be this residue of alcohol in their bloodstream the next morning.

"It is going to completely change the business as we know it."

The Scottish Beer & Pub Association, which represents major brewers and pub groups, said it warned ministers the new limits would confuse consumers and damage trade, noting that "we are beginning to see signs of this happening."

Chief executive Brigid Simmonds added: "This makes the case for further beer tax reductions to support pubs in the Budget even stronger.'

The drink driving limit was lowered in Scotland was lowered to 50mg of alcohol in 100ml of blood from 80mg per 100ml on December 5.

It means the limit in Scotland is now lower than in the rest of the UK.

Greene King said like for like sales in the six weeks to January 11 had been in line with last year, when it registered growth of five per cent.

Excluding Scotland, it said like for like retail sales rose by 0.6 per cent in the last six weeks.

Chief executive Rooney Anand acknowledged the trading impact brought by the change: "Sales were encouraging in our retail business over the important two weeks covering Christmas and the New Year, despite a very tough comparative from last year and softer trading in Scotland, following the introduction of tougher drink driving laws.

"Outside of those weeks, trading was more volatile, with the weeks before Christmas slightly down on the previous year and soft trading since the New Year."

It is not just in the pubs that the new laws are being keenly felt.

Supermarket Tesco has reported sales of non-alcoholic and low alcohol beers have risen by up to 80 per cent in Scotland as many motorists decide not to take any risks.

Scotland fell into line with most of the rest of the EU after it introduced the new limits. England retains the old limits of 80mg per 100ml of blood.

Only 20 people were caught in the month up to New Year by the new limit, according to police figures. The majority of drink-drivers still breaching the old, higher level.

There were 351 people found with more than 50mg of alcohol in 100ml of blood, compared to 434 people caught breaching the old limit of 80mg in the same period last year.

Police chiefs have said the new limits, which were accompanied by a high profile advertising campaign, are acting as a good deterrent.