E-cigarettes are almost twice as effective as nicotine replacements for helping smokers quit, a study suggests, according to the BBC.

A trial found 18% of smokers who used them to quit remained smoke-free after a year, compared with 9.9% of those using nicotine-replacement treatments.

The study of 886 smokers is the first to test how effective modern e-cigarettes are for quitting.

Researchers hope their findings will lead to vaping devices being routinely offered by stop-smoking services.

Public Health England has already called for e-cigarettes to be made available on the NHS within five years, pointing to a body of research that suggests they are at least 95% less harmful than cigarettes.

However, up until now there had been a shortage of evidence on how effective they were as stop-smoking tools.

Lead researcher Prof Peter Hajek, from Queen Mary University of London, said: "Although a large number of smokers report that they have quit smoking successfully with the help of e-cigarettes, health professionals have been reluctant to recommend their use because of the lack of clear evidence from randomised controlled trials.

"This is now likely to change."