Backbench Labour MPs who are opposed to the expansion plans said the new EU laws were "non-negotiable". John Grogan MP, who has led a Commons rebellion with Cabinet support over a third runway, said: "If ministers are not careful, they will find themselves in court." Yesterday former Cabinet minister Lord Smith, now chairman of the Environment Agency, warned that a third runway at Heathrow would make it "impossible" for the Government to meet legally binding targets on air pollution.