The Portuguese Government has objected to Wales proposal for a minimum unit price (MUP) for alcohol.
According to the BBC, the Portuguese government is concerned its country's wines would be "less competitive" in Wales under plans for a minimum price of alcohol warning that the plans could have "direct implications" on the free trade rules of the EU market.
BBC Wales has received a copy of Portugal's "detailed opinion" on the Welsh Government's regulations - a method used by EU countries to object to other member states' plans.
The Portuguese government's economic ministry argues: "There are Portuguese operators who export wines to Wales whose consumer price is lower than the minimum price, therefore the application of a minimum unit price means that many of these wines will suffer an increase in price, which will make them less competitive in that market."
It suggests increased taxation on alcohol could be "less restrictive" than a minimum unit price since it would still offer sellers "the freedom to determine their selling price."
The report states: "Portugal considers the commitment to concerted policies and strategies is imperative, which focus on moderate alcohol consumption and clarify the effects of the excessive consumption of alcohol," it said.
"It is thus possible to safeguard the issue of public health and at the same time (comply) with the principle of the free movement of goods."
New government regulations concerning products imported by member states are subject to a "standstill period" of at least three months, which means a proposed plan cannot be enforced in that time.
But because Portugal has issued a "detailed opinion", the "standstill period" has been extended to 21 August.