Boris Johnson is considering tough new rules for the vehicles that cause most pollution in central London — including a possible ban.
Black cabs would be among those most affected by the introduction of a very low emission zone, which would attempt to improve air quality in the congestion charge area.
The admission came after Assembly member Darren Johnson called for any such zone to apply to black cabs.
The scheme could take years to put into place but the Mayor confirmed it was being investigated.
“We are looking at that, seeing what we can do,” he said. “The congestion charge zone could be a utensil.”
The current congestion charge area extends west to Notting Hill and east to the City. There is also a low emission zone for larger vehicles across London.
“It would be difficult to make the new scheme work,” the Mayor admitted. “There are technical difficulties, I’m told, but we could certainly try it.”
The rules may affect all cars and vans. If applied to black cabs, they could make more than half the taxi fleet undergo modifications to cut their emissions.
Recent research found taxis are responsible for more than a fifth of all particulate pollution in central London.
Assembly member Johnson said: “The Mayor took a big backward step on air pollution when he stopped the six-monthly inspections of black cabs, so he now needs to take an even bigger step forward if he wants to deal with the problem of London’s dreadful air quality.
“A heavy fine to deter the most polluting black cabs and lorries from central London is an essential step towards protecting Londoners’ health.”
The London Taxi Drivers Association general secretary Bob Oddy said: “Draconian rules like this would simply force cabs off the road.”