BBC News
By Roger Harrabin
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Environmentalists are using the law to hound the government to force infrastructure plans into line with its climate change commitments.
Ministers are facing a fusillade of legal challenges on airports, energy and roads.
And now they have been threatened with new legal action unless their airports strategy reflects the drive towards a zero-emissions economy.
A separate legal challenge to the government s road building strategy from campaign group Transport Action Network is already under way.
Earlier this week, campaigners won a battle to force ministers to review their energy policy statement so it reflects climate concerns.