The Government will not extend the liquefied petroleum gas conversion scheme to diesel-powered light goods vehicles because of the time it would take to expand the gas supply infrastructure.
The news comes after the Government decided to implement the voluntary LPG minibus scheme in August, which seeks to convert 4,350 minibuses by 2005.
It means no other types of vehicle will be converted to run on LPG in the short term.
A feasibility study on the conversion of light goods vehicles was completed recently and is being circulated among government departments.
The study concluded that conversions were technically feasible, but highlighted the difficulty in providing an adequate gas supply and refilling infrastructure for 70,000 light goods vehicles.
A senior government official said the limitations lay in the provision of gas storage facilities, as it took at least six years to plan and build additional facilities.