Lead researcher Dr Sarah Jackson, of University College London (UCL), said the public health impact of a “substantially increased” vaping among people who had never smoked regularly depended on what they would have done otherwise.

“Without e-cigarettes, some people might have taken up other forms of cigarettes,” she said.

“In this case, vaping is clearly less harmful.

“However, for those who would not have continued to smoke, long-term regular cigarette smoking is more risky than not vaping.”

The researchers looked at surveys of around 150,000 adults in England between 2016 and 2024.

Respondents who agreed with the statement: “I have never smoked – that is, for a year or more” were counted as “never regular smokers”.

Between 2016 and 2020, only 0.5% of people had vaped.

But by April 2024, that had risen to 3.5%, with more than half aged 18 to 24.

In the past few years, these “never regular smokers” who have started vaping tend to be younger, more female and drinking more alcohol than in the past, the researchers said. Many young people share with friends.

The study, published in the journal The Lancet Public Health and funded by Cancer Research UK, also found that overall vaping among adults is levelling off.

Professor Jamie Brown, a senior research fellow at University College London, said: “These findings remind us that action needs to be taken to minimise the uptake of e-cigarettes by young people who have never smoked cigarettes.

“However, a balance needs to be struck to avoid discouraging smokers from using e-cigarettes to quit smoking.”

Professor Brown said current government plans to ban disposable e-cigarettes were unlikely to be a solution as well-known brands have already launched reusable products that look and cost almost the same.

“The sensible next step would be to introduce stricter regulation of product appearance, packaging and marketing,” he added.

Hazel Cheeseman, chief executive of Action on Smoking and Health (Ash), said the findings were potentially worrying and suggested that a focus on reducing the appeal of e-cigarettes would be the best way to limit their use by non-smokers.

“The aggressive marketing of products to young people means the government urgently needs to reinstate the Tobacco and Electronic Cigarettes Act to regulate the flavours, marketing and branding of e-cigarettes,” she said.

Peter Hajek, professor of clinical psychology at Queen Mary University of London, said: “The Office for National Statistics has just released data showing that the UK smoking rate is below 12%, a record low.

“If much less risky alternatives are allowed to continue to compete with cigarettes, smoking – and the heart disease, lung disease and cancer it causes – will also continue to decline.

“In the UK and the US, where e-cigarettes are allowed, cigarette sales and smoking rates among young people and low-income people are falling significantly faster than in Australia, where e-cigarettes are banned.”

The harm caused by e-cigarettes and cigarettes is definitely greater than that caused by cigarettes. When buying e-cigarettes, you should also identify the e-cigarette brand and choose a regular manufacturer with quality assurance. Many manufacturers make products in accordance with regulations, such as 2% nicotine, which will reduce people’s dependence on cigarettes.