A group of 53 eminent scientists have urged the World Health Organisation (WHO) not to classify e-cigarettes (e-cigs) as tobacco products, arguing that doing so would threaten a major opportunity to reduce smoking-related deaths and diseases.

The open letter to WHO director general Margaret Chan comes ahead of the WHO-sponsored Framework Convention on Tobacco Control (FCTC) meeting in Moscow this October.

A leaked document from a FCTC preparatory meeting has indicated that WHO considers e-cigs a “threat” to public health and wants them classified the same way as regular tobacco products under the FCTC.

In their letter, the international group of scientists claim that e-cigs are “part of the solution” towards reducing smoking rates, not part of the problem.

“These products could be among the most significant health innovations of the 21st century - perhaps saving hundreds of millions of lives. The urge to control and suppress them as tobacco products should be resisted,” the letter said.

Among the signatories is the UK’s public health policy expert Professor Robert West, who last week published research which stated that smokers attempting to quit tobacco were approximately 60% more likely to succeed if they use e-cigs.

“These tobacco harm reduction products could play a significant role in meeting the 2025 UN non-communicable disease objectives by driving down smoking prevalence and cigarette consumption,” the letter added.

It also argued that it would be “counter-productive to ban the advertising” of e-cigs and that the e-cig tax regime should incentivise smokers to switch from tobacco products.

The letter has been warmly welcomed by the e-cig community. Ben Wilson, owner of Freshcig electronic cigarettes, said it represented “a key moment for both consumers and retailers alike”.

“The fact that e cigs don’t contain tar, chemicals or produce carbon monoxide surely demonstrates that they are not as harmful as tobacco, offering a potential lifeline to consumers,” he said.

“If regulation does not come into force then it means that stores can continue to take advantage of the consumer trend for switching from tobacco, with e cigs only carrying 20% VAT and having a higher profit margin,” he added.

The letter also comes just a few days ahead of World No Tobacco Day on 31 May.

In support of the day WHO has called on countries to raise taxes on tobacco to encourage users to stop and prevent other people from becoming addicted to tobacco. WHO estimates that by increasing tobacco taxes by 50%, all countries would reduce the number of smokers by 49 million within the next three years.

“Raising taxes on tobacco is the most effective way to reduce use and save lives,” WHO director general Margaret Chan said. “Determined action on tobacco tax policy hits the industry where it hurts.”