The use of e-cigarettes could be restricted in parts of Britain, after the devolved government in Wales announced proposals on Wednesday to stop smoking the devices in public places.
Wales was the first country in the United Kingdom to vote in favour of a ban on smoking in public places, which came into effect on April 2, 2007.
But Health Minister Mark Drakeford said he was concerned that e-cigarettes would normalise smoking once again, as well as making the smoking ban difficult to enforce.
"We have spent 30 years... creating a climate in this country where people understand that smoking is not something that is to be regarded as glamorous or desirable," he told BBC radio.
"We are concerned that e-cigarettes might reverse that tide.
"We are concerned that they might act as a gateway to conventional cigarettes. It contains nicotine, it's highly addictive and you might then find it easier to move on to conventional cigarettes."
The plans to ban the battery-powered devices, which allow users to inhale a nicotine-laced vapour, will now be put out to public consultation.
E-cigarettes are marketed as aids to quit smoking, but experts say not enough is known about the effects of the chemicals involved, or their effect on people's habits.
Los Angeles City Council last month voted to ban the devices in public places, following the lead of New York, except in specially designated "vaping" lounges or shops.
Several European countries, including Belgium, Luxembourg, Malta, Slovenia and Lithuania, have also banned them in public places, while Italy and France outlaw sales to minors.