Vehicles emitting less than 100g/km of carbon dioxide will be exempt from the London congestion charge from January 4, 2011.

Mayor of London Boris Johnson revealed that the alternative fuel discount would be replaced with the new greener vehicle discount which will exempt any sub-100g/km vehicle that also meets Euro V standards.

This means hybrids that have over 100g/km CO2 will no longer be exempt from the congestion charge.

Drivers have to pay a £10 registration fee to sign up to the greener vehicle discount.

Other changes to the congestion charge include the scrapping of the west London extension and an automatic monthly payment system called CC Auto Pay which will be introduced on January 4 next year.

The daily charge for the congestion charge will rise from £8 to £9 and those that choose not to use the CC Auto Pay system will have to pay £10 or £12 if they choose to pay the following day.