David Hill, senior editor of Red Book, said: 'If congestion charging goes ahead, along with the system of rebates for cleaner fuels, it will have major implications for the LCV market.
'The system would be likely to increase demand for alternative fuel vehicles and this in turn would help to dispel market jitters about their future used values.'
TransportAction says that so far only certain dual-fuel Citroen Berlingo, Ford Transit and Vauxhall Astravan and Combo LCVs qualify for exemption from the £5 per day congestion charge that will be enforced around central London next year.
Livingstone has promised that bi-fuel and hybrid vehicles, will not have to pay the charge so long as they meet PowerShift category 4 emissions criteria.
The Vauxhall Combo Dualfuel qualifies for a 70% PowerShift grant to offset the initial extra outlay, according to Transport Action. Its on the road price is £10,960 — £1,660 more than the petrol version.