A Scottish police force has abandoned a scheme to run its cars on green fuel because the cost of converting them is too high.
Lothian and Borders built up a fleet of 45 to 50 Ford and Vauxhall vehicles that run on LPG, but discontinued the plan when manufacturers stopped fitting the engines in the factory.
That meant the force would have to convert its petrol and diesel vehicles to LPG at a cost of about £2500 each.
LPG fuel, also known as autogas, is 70% cheaper than diesel to use and is also said to reduce carbon monoxide and carbon dioxide emissions.
In 2004, one of Lothian and Borders' LPG Vauxhall Astras was exhibited at the German Liquid Gas Association fair in Leipzig.
A police spokeswoman said: "Lothian and Borders Police stopped using LPG a few years ago.
"The cost implication was too great, particularly given that the cost of converting vehicles to LPG fell to the force after manufacturers stopped supplying them ready-made.
"Our LPG fleet consisted at its height of between 45-50 vehicles, which were a mixture of Ford and Vauxhall."
Alison Johnstone, Green MSP for Lothian, said: "It will continue to be difficult for public services to choose greener vehicles if SNP ministers fail to insist on it being the norm rather than a 'nice to have'.
"The Government has a wishy-washy commitment to reduce carbon from vehicles by raising awareness of funding and slowly rolling out electric charging points.
"Instead they need to divert some of their bloated motorway budget to make electric and low carbon vehicles more affordable so they become commonplace in public sector fleets."
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