Ara Darzi, the chair of the London Health Commission, has advised Mayor Boris Johnson to use existing powers for a ban, which would discourage children from smoking. Smoking is already banned in Britain in public places indoors.
London is not the first city to endorse such measures. New York, for example, has declared all of the city's parks and beaches as smoke-free areas.
But the proposal quickly raised anger. Simon Clark, of the pro-smoking group Forest, says a ban would be "outrageous."
He says, "the next thing you know we'll be banned from smoking in our own gardens in case a whiff of smoke travels over the fence."