Tony Blair has said the government is considering introducing a ban on smoking in public places and will come to a view in the "next few months".
Ministers have so far rejected calls for a ban
But the prime minister stressed it was "a difficult balance" protecting the public's health on the one hand and not being overly interfering on the other.
Mr Blair is a former smoker who quit the day he got married to wife Cherie.
He told BBC Breakfast: "You have got to have some balanced decision making in this, and it's a difficult balance."
He added: "On the one hand it's something that does damage your health - you've got to be careful you don't end up with a [nanny state]."
During an interview timed ahead of next Thursday's local, European and London mayoral elections, he said that various consultations on a ban were underway.
And he hinted the decision might ultimately be left to local authorities.
"In the end, though, you have also got to have some local decision-making in
this," he said.
New York, Ireland and now Norway have introduced smoking bans.
Mr Blair said: "There's no doubt about the damage that smoking does and also I think for a lot of people who aren't smokers they would actually prefer to be in an environment where there's not smoking taking place."
The government has already announced it is assessing the public's feelings about a ban as part of a major consultation on health that will form part of the Public Health White Paper, to be published later this year.
Last month a survey suggested that a majority of Britons favoured a ban.
The poll of more than 1,500 people by market analysts Mintel found 52% support for a ban, including two-thirds of non-smokers.
Around one in three smokers also backed the idea but 25% said they would avoid places where a ban was in force.
Deborah Arnott, director of the anti-smoking charity ASH, welcomed the prime minister's comments.
She said: "Secondhand smoke in the workplace causes about 700 premature deaths every year.
"And we know that ending smoking in workplaces and enclosed public places is the single simplest and most effective thing the government could do to encourage more smokers to quit.
"We would like to see an end to workplace smoking across the country. But new powers for local councils to act in their own areas would be an important and very welcome step in the right direction."
Jean King, Director of Tobacco Control at Cancer Research UK, said: "There is abundant evidence that breathing in other people's tobacco smoke carries serious heath risks, especially for children or those who are chronically exposed, such as at the workplace.
"A ban on smoking in public places - such as is in effect in Ireland and Norway - would safeguard employees and encourage more smokers to quit."
Tim Lord, chief executive of the Tobacco Manufacturers' Association, called on Mr Blair to continue supporting voluntary self-regulation instead of imposing an official ban on smoking in pubs and restaurants.
He said: "The voluntary approach is working in the UK. Self-regulation is already providing more smoke-free places and the choice that the public wants.
"We believe that legislation is unnecessary and would replace successful, voluntarily adopted policies with oppressive and costly bureaucracy, criminalizing smokers and landlords."
Simon Clark, director of the smokers' lobby group FOREST, said: "Any attempt to ban smoking in all public places will be fiercely resisted.
"People are sick and tired of being told how to live their lives. There are
13 million smokers in Britain, some of whom want to quit, but a great many
enjoy smoking and have no intention of giving up just because Nanny Blair
says they should."