A group of 53 leading scientists has written to the World Health Organisation (WHO) urging the body not to classify e-cigarettes as tobacco products.
The experts say e-cigarettes are "part of the solution" in the fight against smoking-related diseases and their use should not be discouraged.
Leaked documents from a WHO meeting suggest the organisation sees e-cigarettes as a "threat" and wants them bracketed along with other products containing nicotine, including regular cigarettes.
More top news
Newly released audio recording of Mohamed Emwazi, aka "Jihadi John", reveals his claims that he was threatened by MI5 five years ago.
"I really think that the focus of your outrage should be people who throw gay men off cliffs", said London Mayor, Boris Johnson.
Archaeologists have discovered eight mass graves holding more than 200 bodies between them hidden beneath a supermarket in Paris.