Provinces that want to crack down on tobacco promotions allowed by federal law are entitled to impose further limits, the Supreme Court of Canada says.
The court issued written reasons Friday backing up a January decision that shot down a tobacco company's suit against a Saskatchewan law banning advertising, display or promotion of tobacco or related products in any store open to children.
In January, the nine judges took the unusual step of issuing an immediate ruling from the bench to uphold the Saskatchewan law, promising reasons later.
Several provinces followed the case closely and some have said they plan to follow the Saskatchewan lead. Manitoba has had a similar law on the books since last year but backed off enforcing it pending the court ruling.
Prince Edward Island says it plans to ban tobacco displays in stores, and Ontario brought in legislation last year that would curb cigarette promotions.
Ontario, Quebec, Nova Scotia, Manitoba, British Columbia and Prince Edward Island were all intervenors in the case, although the justices didn't ask to hear their arguments during the one-hour January hearing.
The January ruling - which fell on Weedless Wednesday, a red-letter day in the anti-smoking calendar - was hailed as a victory for health and a blow to big tobacco.
The Canadian Cancer Society called it a decisive loss for the tobacco industry.
Rothmans, Benson and Hedges, which sought to have the Saskatchewan law thrown out, argued that the federal law - which allows some forms of display of tobacco - should take precedence over the provincial law under what is known as the paramountcy doctrine.
Justice John Major, writing for the unanimous court, said that doctrine doesn't apply because there is no conflict between the two laws.
"There is no inconsistency," he wrote.
"The provincial legislation simply prohibits what Parliament has opted not to prohibit in its own legislation and regulations."
He said the federal law did not grant retailers a right to display such products and the province was within its rights to ban the displays.
The paramountcy doctrine comes into play when compliance with one law could mean defiance of the other, he said.
"It is plain that dual compliance is possible in this case."
He added that the two laws have a similar intent; to combat "a public health evil."