The two biggest tobacco companies in Australia have begun a campaign to undermine the nation's plain packaging laws, ahead of a Department of Health review of the effectiveness of the regulations.

Philip Morris and British American Tobacco have briefed research and data to media outlets as "proof" plain packaging laws have failed, on the eve of their second anniversary on December 1.

Boxed in: Philip Morris and British American Tobacco have released a report attacking plain packaging. Credit:Nic Walker

Philip Morris is promoting "a new piece of independent research that finds there is no evidence that plain packaging for cigarettes is working".

That research, emailed to media by Philip Morris, is titled "The Plain Truth about Plain Packaging: An Econometric Analysis of the Australian 2011 Tobacco Plain Packaging Act".