The Government has agreed to new legislation that will make vehicle CO2 emissions information clearer on new car advertising.
Under the new rules from the Department for Transport (DfT) all promotional literatures, including posters and all print adverts, must include CO2 emission information.
The Government had been facing a legal challenge from the Alliance Against Urban 4x4s and Friends of the Earth for its interpretation of an EU directive on car advertising.
The environmental campaign groups had claimed that the DfT’s guidelines wrongly interpreted the directive by not including posters, billboards and some magazine advertising in the rules.
The green organisations wrote to the DfT in March to point out that the UK wasn't abiding with EU law and warned the Government that they would issue judicial review proceedings if the guidance was not changed.
Now the DfT has agreed to amend the rules meaning fuel consumption and CO2 emissions of vehicles will have to be prominently displayed.
"Until now the UK was getting away with flouting EU legislation on car advertising - but our legal action has closed the loophole,” said Phil Michaels, head of legal at Friends of the Earth.
In its decision letter, the DfT admitted that it had made a mistake: "The Department has been reviewing this guidance and we have concluded that our guidance is incorrect in respect of primarily graphical material.
"For this reason we will be amending this section of the Guidance Note on the VCA website.”