The Government is being lobbied to bring the tobacco plain-packaging bill back to Parliament for a final vote, now the policy has been found to work "almost like a vaccine against tobacco" in Australia.
The health select committee last year supported the bill but the Government has delayed bringing it back to the House pending the outcome of the challenges against the Australian law by the tobacco industry.
But National support partner the Maori Party and lobby group Action on Smoking on Health (Ash) now say the decline in smoking seen in Australia since its "standardised" packaging law came into force in 2013 means New Zealand can dally no longer.
And public health expert Robert Beaglehole, a University of Auckland emeritus professor, says plain packaging in New Zealand "must be passed with urgency".
"The Australian evidence shows standardised packaging of cigarettes has had an immense impact on smoking and has worked almost like a vaccine against tobacco use in children and young people."
Standardised packaging involves removing all brand imagery and colours. The Government-mandated packs in Australia all have the same drab olive-green background with large pictorial health warnings that state "SMOKING KILLS". The aim is to make smoking less attractive, especially among children and teenagers.
Australian survey data shows the prevalence of daily smoking in those aged 14 or older declined from 15.1 per cent in 2010, before the new law came into effect, to 12.8 per cent in 2013.
Canberra is defending its law in two cases: before World Trade Organisation adjudicators in a case brought by tobacco-producing countries including the Dominican Republic, and at a United Nations commission's Permanent Court of Arbitration in a case linked to Hong Kong and tobacco firm Philip Morris Asia.
Maori Party co-leader Te Ururoa Flavell rejected the Government's waiting on the legal challenges. "Waiting for the World Trade Organisation decision means more people die or are sick from smoking-related illnesses. We're tired of standing at the graveside of loved ones who have had their lives cut short from this highly addictive and poisonous drug."
Last week, Ireland became the second country in the world to pass a plain-pack law. British MPs are expected to vote within weeks on introducing the policy to England.
In New Zealand, a UMR survey for Ash last year found 75 per cent support for plain packs, including 55 per cent among smokers, if there was evidence they were less attractive than branded packs to young people.
Associate Health Minister Peseta Sam Lotu-Iiga said he was determined the plain-packs bill would become law.
"Our stance remains the same, that it is prudent to await the World Trade Organisation decision, but as minister I am always looking for ways to bring down the incidence of smoking."
Tobacco companies oppose the plain-packs bill. "Plain packaging is failing in Australia," said British American Tobacco's Australian spokesman, Scott McIntyre.
The firm claimed plain packs had "seen a 32 per cent jump" in Australian teen smoking, from 3.8 per cent in 2010 to 5 in 2013, but the Age reported a Government statistician saying it was not possible to say there had been an increase as the sample size was too small and the change was not statistically significant.