The Government may retreat from its commitment to make all drivers use an increasing proportion of biofuel in their fuel tanks.

Ruth Kelly, the Transport Secretary, announced a study into the impact that the production of biofuels has on the environment. The Department for Transport (DfT) said that it would not support a European plan to increase the proportion of biofuel in petrol and diesel to 10 per cent by 2020 unless it could be proved that it reduced overall greenhouse gas emissions.

The DfT will maintain its Renewable Transport Fuel Obligation, which requires all forecourts to provide 2.5 per cent of their fuel from biofuel sources from April 15.

Ms Kelly said: “We are not prepared to go beyond current UK target levels for biofuels until we are satisfied it can be done sustainably.”

The study will be completed by the summer and, if it finds that the effects on the environment are negative, the plan for forecourts to supply 5 per cent of their fuel from biofuel sources by 2010 could be abandoned.

A report by scientists from the Royal Society last month gave warning that there was a risk that biofuels could damage the environment because their production leads to forest clearance and contributes to greenhouse gas emissions through the fertilisers used to grow them.

Researchers writing in the journal Science last August said that the European plan was less effective in curbing carbon emissions than a programme of restoring forests.

John Sauven, executive director of Greenpeace UK, said: “The Government needs to introduce a moratorium on biofuel targets until this review has been published.”

Suppliers do not have to conform to any minimum standards of sustainability but they do have to report on how the biofuel was produced and what the overall impact on emissions was.

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