Legalising e-cigarettes in Australia could make smoking obsolete and save lives, a British electronic cigarette advocate is poised to tell a parliamentary inquiry in Canberra this week.

Clive Bates, a former director of Action on Smoking and Health in the UK who claims to have no financial links with the tobacco industry, believes vaping products could lead to "one of the greatest public health wins of all time".

In the UK, where e-cigarettes are legal, there is some consensus that smokers should be encouraged to use the devices as a quitting aid. But Australian experts largely want the ban to remain in place.

"It's shocking that Australians are breaking the law and suffering punitive fines if they try to quit smoking using electronic cigarettes," he said.