Australian smoking rates have fallen sharply since plain packaging was introduced, but a landmark challenge to the laws could have implications for other countries mulling similar moves.
This includes France, which is expected Thursday to announce its own plans for stripped-down packaging shorn of tobacco company branding.
Australia pioneered plain packaging in December 2012 in an effort to strip any glamour from smoking and prevent young people taking up the habit.
Experts say it has helped curb consumption, although tobacco companies dispute this.
Government figures show the total consumption of tobacco and cigarettes in the March quarter this year was the lowest ever recorded at Aus$3.405 billion (US$3.01 billion), compared to Aus$3.508 in the December quarter in 2012.
At the same time, tobacco clearances, a taxation measure including excise and customs duty, fell 3.4 percent in 2013 relative to 2012. Clearances are an indicator of tobacco volumes in the Australian market.
Soon after the introduction of plain packaging, Australia also started raising taxes on cigarettes in December 2013 -- the first of four annual hikes each of 12.5 percent over four years. Today, the price of a packet of 20 is around Aus$19, edging towards Aus$1 a stick.
David Currow, who heads the Cancer Institute NSW, said plain packaging had played an important role, pointing to studies that show a significant increase in people calling the national Quitline since it was introduced.
"Since the introduction of plain packaging in 2012, there has been solid, peer-reviewed and transparent evidence of its effectiveness," he said in a recent commentary for Australian newspapers.
Other research pointed to plain packaged cigarettes increasing smokers` desire to give up, he added, and there was also evidence that smokers now increasingly "hide" their packs rather than taking pride in any brand association.
"We are seeing smoking rates drop -- and it is not by accident," he said.
"Smoking is highly addictive, and through this debate we should not lose sight of how difficult it is for someone to give up smoking. But more people are quitting as a result of plain packaging."Data on the number of people who were smoking in December 2012 is not available.
But a national government survey this year showed that the number of daily smokers aged 14 and over dropped from 15.1 percent of the population in 2010 to 12.8 percent last year, continuing a long-running downward trend.
It also said young people were delaying taking up smoking, with the average age now 15.9 years, up from 14.2 years in 2010. Smokers have also cut the number of cigarettes consumed per week from 111 to 96 in the same period.
The big three tobacco companies in Australia -- British American Tobacco, Imperial Tobacco and Philip Morris -- dispute the findings, pointing to alternative sales data.
All cigarettes are now sold in identical, olive-brown packets bearing the same typeface and largely covered with graphic health warnings.
But it has not been an easy ride getting to this point, with the tobacco industry launching unsuccessful legal challenges, arguing that the legislation infringed its intellectual property rights by banning trademarks.
They also claim plain packaging simply fuels the black-market trade with cheap, fake products now more readily available, causing taxpayers to miss out on billions of dollars in excise duties.
Perhaps the biggest threat is still ahead in a challenge at the World Trade Organisation, spearheaded by cigar-producing nations Cuba, the Dominican Republic and Honduras, which say brandless packaging is an assault on their trading rights.
Australia maintains that because plain packaging treats all players equally, it does not constitute discrimination under the so-called TRIPS agreement covering trade and intellectual property rights.