Quebecers will continue to eat white margarine after the Supreme Court rejected Unilever's argument it should be allowed to sell yellow margarine in the province.

• INDEPTH: Canada's conflicted relationship with margarine

The justices ruled immediately after Unilever lawyer Gerald Tremblay's hour-long appearance, rejecting all aspects of his argument.

The court decided it didn't want to hear from the Quebec government or from lawyers for the dairy industry.

The decision to reject the appeal upholds two lower court rulings from the Quebec Superior Court and the Quebec Court of Appeal that the province can prevent the sale of yellow margarine.

Former Quebec premier Robert Bourassa passed the law in 1987, saying it protected the dairy industry and ensured consumers would not confuse margarine with butter.

Unilever, a British-Dutch company, argued that the law reduced margarine sales in Quebec, raised the cost of producing white margarine for Quebec only and contravened the North American Free Trade Agreement and World Trade Organization rules.

But the ruling isn't the end of Quebec's margarine saga.

Quebec will soon have to defend its law under a special committee on interprovincial trade requested by Alberta.