London mayor Ken Livingstone has taken the first steps to ban smoking in all workplaces, including restaurants, pubs and clubs across the capital.

Following new poll results in strong support of such action, he announced an immediate ban on smoking in black cabs and minicabs.

In the past cab drivers had no right to refuse smoking passengers. Now the mayor has instructed the Carriage Office not to take any disciplinary action against a driver who does so.

"I don't believe it is right they should run the health risk of having to breathe in somebody else's smoke," Mr Livingstone said.

The mayor has written to the Health Secretary, Dr John Reid, to request devolved powers allowing him to impose a London-wide ban on smoking.

The call was backed with results of a Mori poll based on 1,007 phone interviews between October 9 and 12.

About 60 per cent of those asked said they strongly supported a complete ban on smoking in taxis, while a further 14 per cent tended to support it.

Two thirds of the respondents favoured a total ban on smoking in workplaces. Three out of four backed a ban in offices, while around 70 per cent approved bans in restaurants and shopping centres.

Another 42 per cent said pubs and bars should be smoke-free.

Due to the health risk posed by dense smoke to staff, the mayor believes such places should still be included in a London-wide ban.

The ban would span across all 32 boroughs, Mr Livingstone continued. As most Londoners don't know all the borough boundaries, it would not make sense to enforce 32 "slightly different" bans.

The chaos predicted by many did not follow bans on public smoking in New York and Ireland, he said.

The mayor has now commissioned further research into how those bans have worked.