London Mayor Ken Livingstone wants vehicles such as 4x4s that emit more than 225g/km of CO2 to pay the higher rate and has asked Transport for London (TfL), which operates the scheme, to investigate the plan.
But fleet vehicles affected by the 2008 charging plan would include versions of the Audi A4, BMW 130, Honda Accord, Mercedes-Benz C-class, Saab 9-3, SEAT Alhambra and Vauxhall Zafira.
Livingstone said: ‘I want TfL to look at lower congestion charges for cars responsible for lower than average CO2 emissions, broadly the retention of the current rate of £8 for most cars, and much steeper charges of perhaps £25 for the really environmentally damaging cars such as the so-called Chelsea Tractors.’
Executives at the British Vehicle Leasing and Rental Industry (BVRLA) say the news comes as little surprise as Livingstone looks for ‘fresh means of raising cash’.
Director-general John Lewis said: ‘Livingstone has to make up his mind. Does he want to reduce traffic on central London streets or does he want a low emission zone by the back door?
‘The latter is what he seems to be aiming at but I just wonder whether all his concern over air quality and climate change merely masks a hidden agenda of raising yet more money for projects such as the 2012 Olympics or the upcoming low emission zone with its already-identified high infrastructure costs.’
A spokesman for the Society of Motor Manufacturers and Traders (SMMT) said: ‘Londoners were sold the idea of congestion charging as a tool to cut congestion but now it appears it is an environmental tax.
‘Such a move would affect a wide variety of cars and not just 4x4s. We also fear that it could be the start of a move to completely ban vehicles from the centre of London.’