Using e-cigarettes in enclosed public places could be banned in Wales under radical new plans.
The Welsh Government said it wants to bring the devices in line with existing smoking laws.
Wales' Health Minister Mark Drakeford said e-cigarettes were a "gateway" to deadly tobacco and risked "renormalising smoking".
The proposals form part of a new Public Health Bill, which also aims to make it illegal to hand over tobacco to under 18s as well as introducing licensing laws for tattooists.
Labour politician Professor Drakeford said: "The bill will mean that anywhere you can't use a conventional cigarette, then you won't be able to use an e-cigarette either. It will prevent the re-normalisation of smoking.
"We have worked so hard in Wales to try and bear down on the harm that smoking does - and allowing e-cigarettes to be used in the way they currently are risks undoing the progress that has been made.
He said last year 5,450 people in Wales died last as a result of diseases linked to tobacco.
Since smoking was banned in enclosed public places in the late noughties there has been a sharp rise in the number of people using e-cigarettes.
Anti-smoking group Ash estimates there are now 2.6 million "vapers" in the UK - with e-cigarette firms frequently marketing their products as being a cheaper and less harmful alternative to conventional smoking.
But the European Society of Cardiology recently warned that while e-cigarettes may be "moderately effective" in helping smokers quit, they needed the same restrictions as cigarettes to avoid uptake by young people and non-smokers.