Claims by tobacco companies that plain packaging will have no effect on smoking are based on “weak evidence” and include studies commissioned by the industry, researchers have said.

Submissions to the UK government by Imperial Tobacco, Japan Tobacco International, Philip Morris and British American Tobacco contained poor quality studies that had not appeared in peer-reviewed journals or were commissioned by the tobacco sector, they said.

Experts from the University of Bath and the UK Centre for Tobacco and Alcohol Studies, writing in the journal BMJ Open, found that only 17 of 77 pieces of data submitted to the government by the industry addressed the impact of standard, plain packs on smoking.

None of the 17 were published in a peer-reviewed journal and 14 of the 17 were either commissioned by or linked to the tobacco industry. This link was not stated in most of the company submissions to the Department of Health’s public consultation on the issue.

They added that evidence cited by the tobacco industry was also of significantly lower quality than other available evidence.