Encouraging cigarette smokers to switch to electronic versions could be a public health 'revolution' and save tens of thousands of lives a year in Britain, a coalition of experts has said.
The World Health Organisation is wrong to call for restrictions on e-cigarettes and instead should be promoting them as a way to quit smoking, it was argued.
A group of leading experts in tobacco controlled have critiqued a report by the WHO on e-cigarettes and said it contained errors and misrepresentations of the evidence.
It has been calculated that for every one million smokers who switch from cigarettes to electronic ones, which deliver nicotine but do not contain tobacco, then 6,000 premature deaths would be prevented every year.
It could mean more than 50,000 lives a year could be saved in England if every smoker switched.
The experts from the department of Epidemiology and Public Health at University College London, the National Addiction Centre at King's College London and the Tobacco Dependence Research Unit at Queen Mary University of London, have published the rebuttal of the WHO report in the journal Addiction.
They said the WHO report says e-cigarette use in the young is a major problem and could act as a gateway to smoking cigarettes where as in fact less than one per cent of children who have never smoked have tried them.
The WHO also said e-cigarettes contain toxins, the health effects are unknown and they should be banned indoors, but the group said the amounts are tiny and similar to that breathed in when walking down a city street.
Finally they said the WHO assertion that e-cigarettes prevent people from giving up cigarettes is not true and that they are actually as helpful as buying nicotine replacement patches from the chemist.
Prof Peter Hajek, from Queen Mary University said: "These WHO recommendations are actually detrimental to public health.
"E-cigarettes could have a revolutionary effect on public health if smokers switch from cigarettes to e-cigarettes."
He said banning them would be akin to saying everyone should keep an open fire in every room of their own in winter because central heating systems may malfunction.
He added that e-cigarettes should be made cheaper than their alternative and they should be permitted in public places where cigarettes are not.
Prof Robert West from UCL said the WHO recommendations were 'puritanical' and 'ridiculous' and did not represent the current evidence on safety or use of e-cigarettes.
He said the evidence shows that smoking rates are continuing to drop as use of e-cigarettes grew, that use of e-cigarettes amongst those who have never smoked is less than 0.2 per cent and using an e-cigarette to help stop smoking is more effective than cold turkey or buying nicotine replacement therapy over the counter, although the NHS stop smoking services still offer the best hope of quitting.
He said: "This is about smokers who are killing themselves. Every day they carry on smoking they lose six hours of life expectancy.
"England has one of the most liberal regimes in terms of e-cigarettes use in the world so if there was going to be a problem it would be here.
"I completely understand concerns about potential risks from this phenomenon but it is vital that public health experts separate opinion from evidence."
Prof Ann NcNeill from King's College London said: "The fact that in England we are not looking to ban e-cigarettes in public places is right and in line with the evidence. But I think there are still concerns about the implications of the European Tobacco Directive.
"It will restrict marketing and the strength of the products which will take off the market some products that help smokers to quit."
She said due to demand from smokers some NHS stop smoking clinics were including e-cigarettes in their quit programmes.