Hundreds of pubs intend to stop serving food to get round the proposed ban on smoking, new research reveals.

According to a poll of publicans, landlords and bar managers, around 40% of firms could escape having to stop people lighting up if the government proceeds with proposals to exempt premises not selling food from a smoke ban.

The survey, commissioned by Cancer Research UK and Action on Smoking and Health (ASH), shows 29% of pubs currently do not serve food. But if the proposed rules come into force, this proportion could increase by a third because of landlords' intentions to shut kitchens.

In poorer areas customers may be able to smoke in up to 50% of pubs, the report added.

Released on the final day of public consultation on banning workplace smoking in England and Wales, the research claimed a partial ban would widen the health gap between rich and poor.

Deborah Arnott, ASH director, said: "This survey shows that the government is threatening to undermine the enormous public health benefits of its smokefree legislation by exempting many pubs and clubs.

"[It] should be the final evidence the government needs to drop the exemptions and get on with bringing in a comprehensive smokefree law."

The current proposals have provoked widespread debate on the extent to which public smoking should be outlawed.

In its submission to the consultation, the Trades Union Congress said exempting some firms would cause a 'confusing mess, harming staff and customers.'

The British Medical Association, meanwhile, hit out at ministers accusing them of double standards for today launching a campaign warning of the dangers of passive smoking.

In contrast, some business groups are concerned trade for firms in the hospitality industry would be hit hard by a ban, while pro-smoking organisations like FOREST claim the vast majority of the public are against an outright prohibition.

Evidence showing the possible effects of a smoke ban was released last week. In its financial report for the last year, pub chain JD Wetherspoons said turnover had dropped by 7% in its bars where smoking has already been banned.

The company admitted there had been 'a significant swing from bar sales to lower-margin food sales and a consequential increase in labour costs.'