The Supreme Court of Canada has ruled against a challenge of the Tobacco Act by Canada's three major cigarette companies, rejecting their push for more advertising leeway.

In February, Imperial Tobacco, JTI Macdonald, and Rothmans, Benson & Hedges challenged the Tobacco Act -- brought in by Jean Chr�tien's Liberal government in 1997 -- saying the restrictive legislation was so vague that it could be interpreted as a total advertising ban.

The legislation bans tobacco companies from advertising in television commercials as well as in markets aimed at young people. In theory, the current law does allow for advertising in adult-oriented magazines, in adult establishments like bars and by direct mail.

However, tobacco companies have refrained from advertising during the last decade of court battles.

The companies argued six parts of the law, claiming they violated their right to free speech in commercial advertising.

In a 9-0 judgment, the court ruled Thursday that the detailed regulations could be justified under the Charter of Rights.

Chief Justice Beverly McLachlin, writing for the unanimous court, said the conclusion was that the law's key provisions "are constitutional in their entirety."

"Parliament's objective of combating the promotion of tobacco products by half-truths and by invitation to false inference constitutes a pressing and substantial objective, capable of justifying limits on the right of free expression," the judges said.

CTV's Rosemary Thompson said the SCC made the decision because of the overwhelming health evidence against smoking.

"The Supreme Court said... there are many provisions under this law that do infringe the Charter but that they're justified," Thompson said from the SCC Thursday.

"The Supreme Court cited the statistics -- that 45,000 Canadians die every year from smoking-related illnesses."

Health Minister Tony Clement called the decision "a victory for all Canadians."

He said Thursday that his office will be monitoring the advertising practices of tobacco companies and ensure that new mediums like text-messaging are not used as loopholes.

"We will be reviewing this act and if there are loopholes in this act we will close them," said Clement.

Anti-smoking advocates

The tobacco companies were up against Ottawa, six intervening provinces -- Ontario, Quebec, Manitoba, New Brunswick, Saskatchewan and B.C. -- and the Canadian Cancer Society.

"The tobacco industry has spent a decade and millions of dollars of legal fees to try and overturn these laws... because this law is going to have an impact on their sales," Rob Cunningham, a lawyer for the Canadian Cancer Society, told Canada AM Thursday before the ruling.

Cunningham said since the law has been enforced over the last decade smoking rates have declined from 30 per cent to 18 per cent.

"Many people will be very surprised that this law does not ban advertising, there's only partial restrictions, even though many other Western democratic countries have total bans on advertising," he said.

The legal debate over tobacco advertising has been going on for nearly 20 years, since Brian Mulroney's Conservative government imposed a ban in 1988 on nearly all forms of advertising by the industry.

That legislation, known as the Tobacco Product Control Act, was overturned by the Supreme Court in 1995 in a close 5-4 judgment.

The ruling found that the government had failed to justify a total ad ban based on public health grounds and had consequently violated the constitutional right of the tobacco industry to free speech.

However, the ruling left room for a more limited set of rules that helped curb advertising directed at young people or the so-called 'lifestyle ads' depicting smokers in various settings.

In 1997, the Tobacco Act was created to meet the Supreme Court guidelines but was quickly challenged by the big three.

Regulation in 2003 also closed a sponsorship loophole that companies had used to have their name displayed at events like the Montreal Grand Prix.

Those rules were upheld by a Quebec trial judge but were further complicated when the case reached a Quebec appeal court in 2005.

There, a three-judge appeal panel upheld key parts of the law which included the bans on lifestyle ads, messages aimed at young people and the government-mandated health warnings on cigarette packages.

However, the panel struck down other portions including a ban on dissemination of 'scientific' research paid for by tobacco firms and another that prohibited ads that left a 'false or erroneous impression' about smoking's health effects.

The court also ruled that Ottawa was right to ban the display of cigarette brand names at sponsored events, but not the use of the corporate names of the parent companies.

With files from The Canadian Press