The federal Treasury has entered the debate over cigarette sales, publishing previously secret information that shows sales falling since the introduction of graphic health warnings and plain packaging.

The Treasury collects data on sales per stick in order to levy tobacco excise, but has until now withheld it from publication to protect commercially sensitive information.

Added to the Health Department's website quietly last week amid debate over the effectiveness of plain packaging, the Treasury data shows 3.4 per cent fewer cigarettes were sold last year than 2012. Plain packaging became mandatory on December 1, 2012.

The Treasury data is consistent with national accounts data that shows a decline of 0.9 per cent in the amount of tobacco and cigarettes sold between 2012 and last year. The national accounts show a further fall of 7.6 per cent in the three months to March after the first of a number of big increases in tobacco excise announced late last year. The Bureau of Statistics bases the national accounts measure on a survey of households, whereas the Treasury collects information on every stick and pouch of tobacco sold.

The Treasury data suggests that, adjusted for population growth of 1.7 per cent, the number of sticks sold per person slid about 5 per cent between 2012 and last year.

The ABS data has consumption of tobacco the lowest ever recorded. Both measures conflict with industry claims that tobacco sales climbed by 59 million sticks or roll-your-own equivalents last year.

The claimed 0.3 per cent increase is said to be sourced from data analysis firm InfoView, although the data behind it has not been released.

Australian Council on Smoking and Health president Mike Daube said the Treasury data was clearly more reliable than unpublished industry figures.

''It's worth noting that in publishing the Treasury data the Health Department said it was an indicator of tobacco volumes in the Australian market. It was a gentle guide to those who need guide dogs and white sticks that these are the most relevant figures,'' he said.

''The whole debate is dishonest. We've always said that the main focus of plain packaging is long term.'' There will be further declines when tobacco excise jumps by 12.5 per cent in December and by 12.5 per cent in December 2015 and 2016. As well, there are six-monthly indexation increases that move in line with average weekly earnings, not the consumer price index.

The Health Department website links to a briefing by Imperial Tobacco chief executive Alison Cooper which says that during the first six months of plain packaging the Australian tobacco market shrank ''roughly 2 to 3 per cent''.

British American Tobacco spokesman Scott McIntyre agreed that smoking rates were declining.

''Smoking rates have been declining in Australia for a very very long time,'' he said. ''But since plain packaging the rate of decline has halved. That's what we are arguing.''

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