Plans to restrict alcoholic drinks sales in Scotland, including the introduction of minimum pricing, cannot be implemented without fresh legislation, opposition parties have warned.

The strategy is too important for individual measures to be tagged on to existing legislation, as the ruling Scottish National Party (SNP) envisages, according to opposition parties in the Scottish Parliament.

Earlier this month, the SNP released its long-awaited strategy to tackle alcohol-related harm. It proposed setting a minimum price per unit of alcohol, as well as introducing a clampdown on special offers in the off-trade and handing local authorities the power to raise the legal age for buying alcohol in shops from 18 to 21.

Mike Rumbles MSP, Liberal Democrat chief whip in the Scottish Parliament, today (11 March) accused the SNP of "wilfully disregarding our national parliament" by attempting to introduce the measures without drawing up a fresh Licensing Bill.

"It is absolutely clear that if they continue trying to sneak through these measures then the entire package would be dead in the water," said Rumbles.

"They need to let MSPs scrutinise fully and vote on controversial measures like minimum pricing, which could have a devastating impact on the whisky industry."

Privately, drinks industry leaders believe the SNP has no fixed idea of how to implement its minimum pricing plans.

A number of drinks trade bodies have also sought legal advice on the issue and found that a minimum pricing scheme would be highly likely to breach EU competition law, just-drinks has been told.

The Scotch Whisky Association has warned, meanwhile, that the proposal could breach international trade law and would set an example that other countries could exploit to maintain high import tariffs on Scotch.

The SNP said itself this month that it needed more time to work with economists on how to implement the pricing scheme.