When I was a feisty junior doctor I considered not treating patients who were smokers. I reckoned I couldn’t help them anywhere near as much as they could help themselves by quitting.

I didn’t of course, but I firmly believe that smoking is so damaging to health we should do anything to stop it.

Then along came e-cigarettes.

They’ve always been controversial and they are creating waves once again after an announcement by the UK’s Medicines and Healthcare Products Regulatory Agency that it will look favourably on licence applications from e-cig firms so doctors can prescribe them to patients wanting to kick the habit.

This has set the cat among the pigeons.

Opponents are sparring in the pages of the BMJ, with Professor ­Nicholas S Hopkinson of the National Heart and Lung Institute in the YES corner, and Professor Jørgen Vestbo and colleagues of Manchester University in the NO camp.

Vestbo argues no country in the world other than the UK will give a licence to classify e-cigarettes as drugs, and for good reason.

E-cigarettes as an aid to stopping smoking has not been endorsed by a single major scientific society because their effectiveness is unproven.

In the most cited trial comparing e-cigarettes with medicinal nicotine products, e-cigarettes were found to be superior, showing a one year abstinence rate of 18%, compared with 10% for medicinal nicotine.

However, twice as many people in the nicotine group were found to have quit nicotine completely, as people using e-cigarettes tend to continue vaping, whereas most people using medicinal nicotine quit.

The YES camp emphasises that e-cigarette users inhale vapour created by heating liquid containing a ­humectant to retain moisture, ­nicotine and flavourings.

E-cigs of course aren’t completely safe but they don’t contain the most toxic component of tobacco smoke – solid tar particulates – nor carbon monoxide.

Users’ exposure to other constituents in e-cigs is far lower than in people who smoke.

The Government’s independent Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment describes the risk of adverse health effects from vaping as “substantially lower” than smoking.

A respected Cochrane review supports e-cigarettes as a smoking cessation aid, as does recently updated guidance from the National Institute for Health and Care Excellence.

Tobacco cigarettes have never been subjected to regulatory scrutiny and would never get a licence if they were.

But a licence for e-cigs and the associated scrutiny they would receive could improve consumer confidence and reverse false beliefs about relative harm when compared with smoking.

Remember, the UK’s aim is to be smoke-free by 2030.