A complete ban on smoking in pubs and bars could be reality in London within two years, according to American anti-smoking ambassador Professor Stan Glantz.
Prof Glantz caused concern in the trade when he visited the Greater London Assembly (GLA) to push for a complete ban on smoking.
He is the man who spearheaded California's ban on smoking in bars and restaurants, and the assembly wanted to hear his advice.
But a spokeswoman for the GLA insisted that it was listening to views on both sides.
"We will gather the information together and make our recommendation to the Department of Health and possibly the Mayor of London," she said.
"We know that pubs are a big part of this and many are concerned that smoking could be banned, but we are also listening to the views from those groups that want a smoking ban."
Prof Glantz told the GLA last month that a workplace ban would be the first step to introducing a no-smoking policy in the city. It would be followed, within two years, by a complete ban in pubs and restaurants.
Amanda Sanford of Action for Smoking and Health (ASH) said that she thought the assembly would recommend that the trade self-regulates and implements the Public Places Charter (PPC).
She added: "I don't think it is going to ban smoking outright, but action from both the trade and the Government is long overdue."
Prof Glantz's comments followed the news that the Government had scrapped initial plans for curbs on smoking in pubs after lobbying from the trade. It rejected advice from the Health and Safety Commission after ministers decided to give more weight to self-regulation.
John Bristow, of the Guild of Master Victuallers, said: "I agree with self-regulation in the form of the PPC. I have a sign outside stating that the pub is smoking throughout but that ventilation is provided."
The results from the Charter Group's nationwide survey into how many pubs are complying are not yet available.
Nick Bish, chairman of the group, said that at the last informal count in January around 10 per cent of the nation's 60,000 pubs had signed. "We need to get about half of the pubs signed up so that we can prove to the Government that it does not need to legislate," he said.