Some New Zealand tobacco researchers are calling for the government to allow e-cigarettes containing small amounts of nicotine to be sold here, in the same way nicotine patches are.
Academics say research shows e-cigarettes are one way smokers can reduce their nicotine intake and lead healthier lives.
They are calling on the Ministry of Health to loosen rules which prevent them being sold in New Zealand.
People inhale and exhale the liquid vapour produced by an electronic cigarette, otherwise known as a vapouriser.
But while it's illegal in New Zealand to sell ones with nicotine, the UK Government backs their use and allows them to be sold everywhere, including in supermarkets and corner shops.
Prime Minister David Cameron made a speech last month in support of the electronic cigarettes.
"I think we do need to be guided by the experts...one million people are estimated to have used e-cigarettes to help them quit or have replaced smoking with e-cigarettes completely."
E-cigarettes were a "very legitimate path" for many people to improve their health, he said.
Calls for NZ to change its rules
In New Zealand, only Ministry of Health-approved nicotine replacement therapies such as patches and gum can be sold.
The ministry's website states: "there is not enough evidence to be able to recommend e-cigarettes as an aid to quit".
But Massey University College of Health associate professor Marewa Glover said nicotine content in e-cigarettes was no more harmful than that found in legal quitting aids such as patches.
"They should just be on the market as a consumer product. They are 95 percent safer than smoking cigarettes, I don't even think they rate as a health issue actually. The toxins in vapour is miniscule compared to a cigarette.
"There's no known harms occurring to people who vape, in fact there are some studies showing that people, even if they still are smoking and vaping, they are experiencing improvements in their health."
The ministry needed to acknowledge the research, she said.
"Electronic cigarettes are a very challenging concept to our existing public health and tobacco control sector that's been operating on a 'quit or die' paradigm. So, it's 'you quit my way, or the highway'."
Rebecca Ruwhiu-Collins is a stop-smoking health worker.
She established an e-cigarette group with seven women from Glen Innes, Auckland, in November last year and six quit smoking within the six-week programme.
"I am just amazed. I've done groups with just stop smoking medicines that the Ministry of Health stand by. I've done many groups using these medicines.
"Even in this group I have offered them other stop smoking medicines if they didn't want to use the vapourisers, but this is probably the first time where you don't have people coming back each week having [had] this real tough week."
Peter Hajek is a professor of clinical psychology and director of the Tobacco Dependence Research Unit at Queen Mary University of London.
He co-wrote a report for Public Health England, a government executive agency.
It concluded that e-cigarettes were significantly less harmful to health than tobacco and have the potential to help smokers quit smoking.
Professor Hajek said New Zealand's Ministry of Health should allow e-cigarettes to be sold here.
"We have a serious problem here because it's favouring cigarettes over their competitor so this is all helping the tobacco industry to carry on selling the dangerous stuff and provides a disincentive to anybody trying to do anything safer. It's really a scandal."
Research in England showed e-cigarettes were not a gateway drug for children or non-smokers, Professor Hajek said.
"It's so patently obvious that people could limit the harm to their health and it's not happening because the regulators are trying to actually protect cigarettes.
"It's not that they want to do this it's an unintended consequence."
University of Canterbury adjunct professor, doctor Murray Laugesen's research showed nicotine levels in e-cigarettes were half-to-two thirds that of a normal cigarette, but toxicity levels were 100 times lower.
There should be one rule for everyone so people could vape in the same way they can smoke tobacco, he said.
More research needed, health advocates say
But the co-director of a research group at the University of Otago aiming to make the country tobacco-free by 2025, disagreed.
Janet Hoek of ASPIRE 2025, who is also a Professor in the Department of Marketing at the University of Otago, said to be responsible, New Zealand had to take a more conservative stance.
"The decision about what is the most effective treatment absolutely has to be evidence-based. We don't want to give something to people that might have health risks that haven't yet been identified, but will come back to haunt them in say, 10 or 15 years time.
"We really don't want a situation where we're re-introducing something like smoke tobacco which was initially touted as bringing some health benefits."
Professor Hoek believed the ministry was driven by evidence and would be open to adopting a more liberal approach to regulating e-cigarettes if there was evidence which proved it was beneficial to people's health.
No one from the ministry was available for an interview but it said in a statement that it continued to assess new evidence as it arose.
The long term impact of using e-cigarettes was still unknown, it said.