Plain packaging and higher cigarette prices appear to have done more than cut the number of people who smoke. They've also cut the amount remaining smokers smoke.

Official surveys conducted by the Institute of Health and Welfare and the Bureau of Statistics find that in the past decade the number of Australians smoking has fallen 25 per cent. But an analysis of the December quarter Australian National Accounts conducted by health policy specialist Martyn Goddard finds the volume of tobacco consumed over those 10 years has fallen 48 per cent.

Smokers would be hit by another series of tax increases under the Labor plan.

He says the difference can only be explained by the remaining smokers smoking less – at least 30 per cent less.

"It might well be more, because people who successfully quit are more likely to be low to moderate smokers than those who remain."