Speaking after last week's debate in Parliament, Mr Lamont, Shadow Cabinet Secretary for Justice, said: "We welcome some of the proposals in this legislation, such as stopping alcohol from being sold below cost price. After all, Scotland has serious problems with alcohol abuse that need to be addressed.
"However, the proposals for minimum pricing have simply not been properly thought through.
"As well as being of dubious legality and based on very limited evidence, the proposal to introduce a blanket minimum price for alcohol would hit off-licences and other businesses in the Borders.
"Having significantly different prices between Scotland and the rest of the UK would undoubtedly lead to cross border trade where people would simply take advantage of cheaper prices in Berwick or Carlisle, at the expense of local retailers in the Borders.
"There is considerable evidence of this "booze cruise" culture in Ireland, where shoppers from the Republic travel to the North to take advantage of cheaper alcohol prices.
"Not only could this hit businesses in the Borders, but it could also encourage people to buy more alcohol than they originally intended, which undermines the fundamental purpose of the legislation.
"The Scottish Government must properly think through the implications of this proposal and come back with a more coherent and joined up approach to dealing with this serious problem."
This view will not go down well with South of Scotland list MSP Christine Grahame (SNP) who is urging politicians from across the political spectrum to back the Scottish Government plans.
She said: "It is time for politicians from all parties to unite so that we can tackle this issue head on. All the evidence points to a clear link between pricing and consumption and we cannot afford to let Scotland's alcohol problem continue to fester.
"Scotland's notorious relationship with alcohol is not a new problem, but is one that is getting progressively worse as low priced, high strength alcohol becomes more widely available."
Problems caused by alcohol are estimated to cost the country 3.56 billion every year: half of all prisoners in Scotland's prisons were drunk at the time they committed their offence; and an estimated one in twenty deaths in Scotland can be attributed to alcohol.
Ms Grahame added: "We must be prepared to try bold, radical solutions and the measures contained in the Scottish Government's proposals – including minimum pricing – are urgently needed."