A major British medical organisation has called for the promotion of e-cigarettes as a safe alternative to smoking - a move at odds with Australian medical experts and authorities.
The Royal College of Physicians on Thursday released a report concluding e-cigarettes were likely to be beneficial to UK public health, insisting their use should be encouraged.
It also pours cold water on the argument that the devices could act as a gateway to smoking.
The position stands in stark contrast to that of the Royal Australasian College of Physicians, whose president Nick Talley has previously warned e-cigarettes glamorise smoking.
He's warned of a huge risk that allowing widespread use of e-cigarettes will inadvertently renormalise smoking behaviour.
The Australian Medical Association has made similar warnings, expressing significant concerns about the devices and their potential to act as a gateway to tobacco smoking.
Thursday's report rejects that idea and says e-cigarettes can actually act as a gateway from smoking, with no evidence e-cigarettes are renormalising smoking.
The evidence indicates e-cigarettes are being used almost exclusively as safer alternatives to smoked tobacco by smokers trying to reduce harm to themselves or others, or quit smoking completely, the report says.
"This report lays to rest almost all of the concerns over these products and concludes that with sensible regulation, electronic cigarettes have the potential to make a major contribution towards preventing the premature death, disease and social inequalities in health that smoking currently causes in the UK," author Professor John Britton said.
"Smokers should be reassured that these products can help them quit all tobacco use forever."
E-cigarette devices are legal in Australia but the nicotine used in them is classified as a Schedule 7 dangerous poison, the sale and possession of which is illegal.
University of Sydney public health Professor Simon Chapman says researchers in the UK are unique in their "extreme enthusiasm" for e-cigarettes.
"They're quite blind to some of the concerns that people in other countries are expressing," he told AAP.
"They've only been around e-cigarettes since about 2007 and that's a very, very short period by which to determine whether they are as safe as everybody hopes they will be."
AMA vice president Stephen Parnis says the AMA is still concerned about the risks of the relatively-new phenomenon.
Big tobacco has a huge financial interest in the devices, he said.
"We have not seen to this point evidence that contradicts the idea that putting something in your mouth, a stick-like device, and inhaling is not risky."
Tobacco giant Philip Morris sells e-cigarettes in Japan and some European countries while e-cigarette company Nicoventures is owned by British American Tobacco.