Andrew Williams wants government to look into excise tax "loophole".

British American Tobacco has joined Philip Morris in attacking anti-smoking regulations.

From Wednesday, July 1, the government will raise the excise duty on all spirits by at least 2.8%.

The tax hike comes as the Law Commission is mulling its recommendations on raising the excise tax further in a report due at the end of the year.

The Law Commission appears to be using as its base for policy recommendations a controversial study into the social costs of alcohol undertaken by Wellington economics group Berl for ACC and the Ministry of Health.