Controversial areas include a proposed ban on smoking in bars, similar to those in Ireland and Norway, which Dr Lo believes will make compromises necessary to pass the legislation.

'Legco is a place of give and take, and there might be areas of compromise which will defeat the original purpose of the bill,' said Dr Lo, a member of the Hong Kong Council on Smoking and Health.

Government sources said last week they expected the reforms to be made law by year's end, but warned that the situation could change.

Most politicians and lobbyists interviewed by the Sunday Morning Post, such as Dr Lo and his successor in Legco, Kwok Ka-ki, expect amendments to the ordinance to be passed eventually with compromises made by the government.

Dr Lo believes the government's end-of-year deadline for passing the legislation is too optimistic, and opts instead for next year.

Others believe the proposed one-year transition period for bars and restaurants to go smoke-free may be extended to 18 months - which would expose catering staff to further health risks.

One of the biggest areas of concern is the exclusion of mahjong parlours and bathhouses from the smoking ban on public indoor places. Government sources have said they were exempted since the vast majority of their clients are smokers.

Anthony Hedley, director for the University of Hong Kong's Tobacco Control Research and Policy Unit, said this may create loopholes to circumvent the ban.

'I don't think it is a sensible thing to start with exceptions and exemptions, because it creates precedents,' he said, adding that much hinged on how the law was drafted.

Dr Kwok said an option that could be viable was allowing smoking rooms. He said smoking rooms would have to meet stringent requirements.

Legco members would also have to be convinced the rooms would help protect the health of the public.