Plans to charge drivers of diesel cars about £10 to drive into central London are being considered.
The levy would be on top of the current £11.50 congestion charge for driving into the centre of the capital.
The Mayor wants the new Ultra Low Emission Zone (ULEZ) to be introduced by 2020.
The Times newspaper says he will also lobby the government to increase vehicle excise duty on diesel cars to encourage motorists to move to cleaner vehicles.
Only diesel vehicles meeting the Euro 6 emissions standard will be exempt, while petrol cars registered before 2006 will also have to pay the new charge.
All new cars sold from 1 January 2015 must meet the Euro 6 emissions standard, a stringent European Union directive to cut exhaust pollutants which targets a cut in nitrogen dioxide, seen as an air pollutant.
London, in breach of European targets on air pollution:
A spokesman for the mayor said the plans will be subject to a full consultation and any levy on cars not meeting the Euro 6 emissions standard would be “likely to be a similar amount to the congestion charge”.
The mayor’s environment adviser, Matthew Pencharz, said: “Over recent years the Euro diesel engine standards have not delivered the emission savings expected, yet governments have been incentivising us to buy them.
The most worrying aspect of this new measure is that Boris has made no statement about an exemption for Taxis and Private Hire.
If this measure is bought in without exemption, many drivers and most garages hiring out Taxis would face a major financial difficulty.
The secondhand value of virtually all Euro 5 or lower vehicles will fall through the floor. We need a statement from Boris as soon as possible about the future of pre Euro 6 vehicles.
Boris isn’t banning polluting vehicles, he’s just squeezing money out of drivers who have had no choice in the vehicles available to them to buy and is raising funds with another tax on hard working Taxi trade.
The problem being NO2 and NOx emissions:
Boris also consciously ignored health considerations attached to the production of new Taxi vehicles. His age limit policy (signed off by the United Trade Group without consultation of their membership) removed thousands of older vehicles from service, consciously knowing they were less polluting in the area of NO2 and NOx particle production.
This new measure isn’t about health or cleaner air for London. It’s all about the money (AGAIN).