Health Secretary Nicola Sturgeon has admitted that European law will provide "hurdles" to minimum pricing rules, but insists it will not prohibit their introduction.
She hit back at Tory Deputy leader Murdo Fraser, who used his party's debate at Holyrood to suggest the controversial move "may well be illegal".
In his opening speech, Mr Fraser cited a recent ruling from the European Court against price limitations imposed on tobacco for health reasons.
He insisted: "We have called previously for the Scottish Government to publish its legal advice stating whether minimum pricing of alcohol would breach EU rules.
"If the Government is to be taken seriously on this issue then it must publish that advice without delay."
He also claimed the SNPs plans would see the price of Stowells wine increase, but the price of Buckfast remain the same.
The Health Secretary dismissed his claims as "long on assertions and short on any hard evidence".
However, Labour's new Health spokesperson Jackie Bailey seconded his call, claiming there was a "precedent" in place for the Government to release its legal advice to opposition party leaders.
Ms Sturgeon denied that, but said: "If there are precedents, I am willing to discuss them." She used her time in the debate to insist the moves would not penalise either the whisky industry or responsible drinkers.
She said: "The greatest impact would be on strong, cheap alcohol, which is favoured by harmful and hazardous drinkers, and not on mainstream and premium products."
The Health Secretary stated: "These are the facts and it is because of these facts that our proposals are backed by a powerful coalition of opinion in Scotland - backed by doctors, backed by nurses, backed by the police, the Chief Medical Officer, and backed by the licensed trade association."
However, Tory Justice Spokesman Bill Aitken said laws were already in place to stop binge drinking. He cited laws against continuing to drink in pubs when intoxicated, and against landlords continuing to serve drunk patrons and suggested this meant more could already be done by licensing authorities.
The Liberal Democrats also called for tougher enforcement of existing laws, and questioned the sense of minimum pricing if Scots were still able to drive over the border and "fill up a van."
The Lib Dems and Tories remain united against minimum pricing, but Labour have still refused to support or oppose the proposals.
Jackie Bailey insisted she would not be rushed into making a judgement, saying she wanted to do justice to a serious issue which deserved thoughtful consideration.
MSPs will vote on a Tory motion to reject the proposals at 5pm on Thursday.
