Programmes, managed by the Energy Saving Trust such as Powershift and CleanUp, had offered £14m in grants for car buyers and vehicle operators, to help create a better market for environmentally friendly vehicles. These were scrapped in March.
Six similar schemes have since been submitted by the Department for Transport but so far only one has been given approval by the European Commission.
James Kelsey, a member of the motor trade group at national accountancy firm UHY Hacker Young, said: "Interference by the EU means that it will take months for any of these schemes to get off the ground. This could mean that customers who want to buy an environmentally friendly vehicle may wait until incentives are in place before they buy.
"People who had only considered buying a green vehicle because of the grants may now be put off completely. This will not only cost the environment, but will also hit motor retailers selling green vehicles in the pocket."