Smoking at the bar in a third of British pubs is to be banned, says the British Beer and Pub Association.
Up to 80% of pub space is expected to become non-smoking
The body claims that around 22,000 bars and pubs will enforce a ban before the end of next year.
Five chains have signed up for the measure after customers were questioned on their preferences.
Simon Clark, director of smokers' rights group Forest, said: "We support these proposals to a degree because they still allow an element of choice."
The British Beer and Pub Association hopes that within five years around 80% of pub space will eventually become non-smoking.
But the measure falls short of a complete ban on smoking in pubs.
Mitchells & Butlers, Punch Pub Company, Scottish &
Newcastle Pub Enterprises and Spirit Group and Enterprise Inns are all planning to enforce the ban.
According to Mitchells & Butlers, smoking will be restricted to 65% of floor space by the end of 2005 in over 2,000 of its outlets, which include All Bar One and O'Neill's.
The chain also claims around 50% of restaurant space will become non-smoking by next year and a ban will be enforced in "back of house" areas such as cellars, storage areas, kitchens and corridors.
Chief executive Tim Clarke said: "The policy is the results of careful consideration of the needs of both smokers and non-smokers, and demonstrates the
best way to provide choice for all of our customers".
British Beer and Pub Association spokesman Mark Hastings believes a total ban would prove costly and be legally complicated to implement.
He added: "Clearly they (the chains) recognise
non-smoking is on the increase and they want to reflect that. But we also believe in freedom of choice.
"While customers want more restrictions on smoking, only 20% would support a total ban in pubs - that is (from) a Department of Health survey on this".
Mr Hastings also claims Ireland has seen a 15% drop in trade following the introduction of a total smoking ban in pubs.
He says that if the same thing happened in the UK and had the same impact, 5,000 pubs would be shut and
75,000 jobs lost.
Mr Clark, director of smokers' rights group Forest, cautiously welcomed the proposals and said: "It is clear from opinion polls that there is little support for a blanket ban in pubs.
"It is up to individual pubs to choose a policy on smoking but there needs to be a degree of flexibility."
But anti-smoking group Ash (Action on Smoking and Health) said the measures were ineffective.
Ash spokesman Ian Willmore said: "These proposals are entirely sinadequate in dealing with the problem because around 33,000 pubs are completely excluded.
'We want a complete ban'
"More importantly they don't protect staff adequately because they will still have to work in areas where they will be exposed to people smoking.
"We want legislation that ensures that smoking in the work place is banned completely, including pubs."
Under current health and safety laws steps need to be taken by employers to ensure there is sufficient fresh air in enclosed workplaces including pubs.
They also state that in rest rooms, appropriate measures must be introduced for the protection of non-smokers against discomfort caused by tobacco smoke.