Government plans to ban smoking only in public places that serve food are likely to widen health divisions between the rich and poor, according to medical experts.
A new report published in the British Medical Journal (BMJ) estimates that up to two-thirds of pubs in deprived areas could be exempt from the smoking ban under current Government proposals.
The Government's White Paper Choosing Health proposes that smoking should be outlawed only in pubs serving food, from 2009.
Private members' clubs and licensed premises that don't serve food would be exempt.
But a study of the borough of Telford and Wrekin in Shropshire found that out of 174 pubs, 43% would be exempt, and 56% of all licensed establishments would not have to implement a ban on smoking.
The BMJ report contradicts Government predictions that only 10-30% of pubs would be able to allow smoking under its proposals.
It concluded: "It is more likely that the poorest people with the worst health and highest smoking prevalence would be those most likely to be harmed by passive smoking, either working in pubs or as customers, and would be those most likely to have their attempt to stop smoking undermined."
Action on Smoking and Health director Deborah Arnott said: "Smoke-free legislation must be comprehensive if it is to be successful."