The Scottish Government claims the new law could save dozens of lives every year, but the Scotch Whisky Association (SWA) yesterday launched a two-pronged challenge to the legislation.
The association, which represents the Scottish whisky industry, is lodging a complaint with the European Commission (EC) and pursuing action through the Court of Session in Scotland.
Holyrood passed the Alcohol Minimum Pricing Bill in May, which the Government said was aimed at helping to address alcohol misuse. It would establish a minimum unit price of 50p.
The SWA says it believes the measure is illegal, ineffective and will damage the Scotch whisky industry.
Chief executive Gavin Hewitt said the association's action was backed by other UK and European Union wine, beer and spirits organisations.
The implementation date of April next year could now be pushed back.
The complaint to the EC could take around 12 months to be processed, while an initial hearing at the Court of Session is anticipated to take place in the autumn, Mr Hewitt said.
Health Secretary Nicola Sturgeon said: "We firmly believe minimum pricing meets the legal tests and we will vigorously defend this challenge."
The legislation was backed by health professionals, police chiefs and some in the drinks industry.
Dr Alan McDevitt, deputy chairman of the British Medical Association's Scottish General Practitioners' Committee, said: "This announcement is disappointing, but not entirely surprising.
"Research published shows one in four people admitted to intensive care units in Scotland has an alcohol problem. There is an urgent need for action."
Dr Evelyn Gillan, chief executive of Alcohol Focus Scotland, said: "Minimum pricing will bring significant health benefits, so to contest this makes it clear some sections of the alcohol industry are motivated by profit, not public interest."
Liberal Democrat leader Willie Rennie said: "Cheap drink leads to more people drinking more, which results in greater harm to their health.
"Instead of seeking to block minimum pricing, the drinks industry should be working with Government to make it work effectively."
Conservative health spokesman Jackson Carlaw said he hoped the policy will be adopted.
A Labour spokesman said: "Labour urged the Scottish Government to clarify and put beyond doubt their thinking on the legal advice at an early legislative stage, which could have avoided this."
The UK Government has suggested setting a minimum price of 40p per unit for England and Wales, and talks are taking place about introducing a minimum price in Ireland and Northern Ireland.
The SWA's complaint to the EC centres on the argument that minimum pricing breaches EU trade rules.
It says the measure would artificially distort trade in the alcoholic drinks market, contrary to EU law.
Part of its Court of Session action argues the policy exceeds the Scottish Parliament's powers under the Scotland Act 1998 because it relates to the price of goods and services, reserved to Westminster.
Mr Hewitt said the association is also concerned other countries are likely to adopt measures similar to minimum pricing, using protection of health as justification, in order to target imported products such as Scotch whisky in a move that could cost the industry £500 million.
He added: "We consistently argued minimum unit pricing will be ineffective in tackling alcohol misuse. It will penalise responsible drinkers and put even more pressure on their household budgets."
Research shows 73% of alcohol sold in the "off trade" will have to go up in price, Mr Hewitt said.
Sheffield University researchers had said there could be 300 fewer deaths annually, 6500 fewer hospital admissions and overall savings worth £942m after 10 years should the minimum price be put in place.
However, the SWA said aspects of the research had been described by one expert as "no better than a weather forecast" in terms of accuracy. It also said it would be "impossible to evaluate the success or otherwise of minimum pricing on this basis".
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