New research has added weight to calls for a ban on smoking in all workplaces - including pubs.
The British Medical Association published research last week that showed passive smoking by staff could put them at risk of developing heart disease.
This could prompt ministers to reconsider introducing a smoking ban in pubs - which, it is feared, would severely hit trade for licensees.
According to its study, non-smokers who are exposed to environmental tobacco smoke for at least 30 minutes a day are at far greater risk of developing acute coronary syndromes compared with those who are not exposed.
And the study found that exposure at work was associated with a greater risk than that at home.
The association concluded that the only safe way to protect non-smokers from exposure to cigarette smoke is to eliminate smoke completely from all public places and workplaces - including pubs.
But the trade has been arguing for self regulation in the form of a voluntary charter recommending the use of signage, with no-smoking areas and ventilation where possible.
Nick Bish, spokesman for the trade's Charter Group, said the association hadn't considered the huge effect such a ban would have on the hospitality and leisure industry.
He added: "The charter addresses this and is looking at reasonable and practical ways to address passive smoking bearing in mind the hospitality and leisure industry and the huge number of people who want to come into a pub or restaurant and be able to smoke."
The Publican's Market Report suggests the trade is in line to smash the 50 per cent charter compliance target agreed with the government, with 64 per cent of pubs already signed up.