Claims that the residual values of existing hybrid vehicles could be severely reduced under Transport for London’s proposed changes to the capital’s congestion charge have been rejected by experts.

The Society of Motor Manufacturers and Traders said TfL’s proposal to replace the current Alternative Fuel Discount with a Greener Vehicle Discount would encourage a switch to much cleaner and more CO2 efficient cars.

This, it said will damage the RVs of existing hybrid models.

“Early adopters of low-carbon technologies, for example those who have recently purchased Euro4 standard hybrids will likely see significant impacts on the resale value of their vehicles as well as be penalised for early-adoption on current technologies available on the market. This is both unfair and market distorting,” said the SMMT.

However, experts at CAP have rejected this claim. “Withdrawing the alternative fuel discount would reduce demand for hybrids that do not meet the proposed Greener Vehicle Discount criteria among used car buyers who are regularly exposed to the congestion charge,” said a CAP spokesman.

“There will be some impact on the desirability of such models in and around the capital but this will not lead to a universal reduction in residual values. Any local impact on values is not quantifiable without evidence and could probably be mitigated simply by selling the cars elsewhere."

The proposed changes would mean a 100% discount for cars that emit 100g/km of CO2 or less and meet the Euro5 standard.