Plans for a smoking ban in England appear to be in disarray after Cabinet ministers failed to agree on whether there should be exemptions.
The ban proposals went out to public consultation in June
Health Secretary Patricia Hewitt had hoped to give pubs and restaurants the freedom to set aside a room for smoking where staff would not have to work.
But her Cabinet colleagues failed to back the move during a meeting on Monday, the BBC has learned.
Ministers also rejected Ms Hewitt's plans to ban smoking in private clubs.
The failure to reach agreement raises doubts over whether the government will be able to introduce its new Health Improvement Bill into Parliament as expected this Wednesday.
One government source said: "The important thing is that choice [for smokers] remains.
"How it will be done is a matter for discussion. The method has not been resolved."
Ms Hewitt proposes banning smoking in all pubs and clubs. She also wants one room set aside in each building for smokers where no drinks would be served.
The government originally planned a partial ban but decided it would be unworkable.
Culture Secretary Tessa Jowell is leading criticism of the loophole allowing only "smoking carriage" rooms where staff would not work.
She has written to anti-smoking group Ash to voice her concerns, which are thought to be shared by David Blunkett and David Miliband.
Trade unions have also opposed the move, saying that bar staff will still have to inhale smoke when they clean the special rooms.
A ban on smoking in all enclosed public places will begin in Scotland next March. Northern Ireland has also agreed a ban - which is already in place in the Republic of Ireland.
The plans are causing concern among publicans.
The Federation of Licensed Victuallers' Associations, which represents self-employed licensees, says a ban could mean a 10% fall in business. The federation's chief executive, Tony Payne, told the Daily Telegraph: "A cigarette and a pint are important for a lot of working people at the end of a day and they will end up having them at home instead."
The British Beer and Pubs Association wants limits on smoking at bars to be phased in.
Its spokesman Mark Hastings said the idea of a smoking room would be welcome but he wanted to see the details.
The British Medical Association is still pushing for a complete ban with no exceptions.