A partial ban on smoking in enclosed public spaces will make health inequalities worse, researchers claim.
MPs are due to vote on the ban next week
The Government is due to vote next week to outlaw smoking in most public places, with exemptions for non-food pubs and private members' clubs.
A team from Croydon Primary Care Trust, south London, say the ban will increase the health gap between rich and poor.
The ban will see "a disproportionate increase in the number of smoke-free pubs in affluent areas", they claim.
A snapshot survey of almost 500 randomly selected pubs across England was carried out for the study.
These were considered along with the levels of deprivation people living nearby were exposed to.
The pubs were then contacted to find out whether or not they served hot food to determine whether they would be affected by the smoking ban.
Researchers found a strong link between wealthy areas and pubs selling food, and poor areas and pubs not serving food.
Therefore, they concluded, people in the poorest areas would not be as well protected against the effects of passive smoking because fewer pubs would be subject to the ban.