The four councils opposing expansion – representing more than one million residents – insist that the proposals’ “Achilles heel” is the risk they pose to air quality.
The threat of a legal challenge comes in response to an announcement on yesterday by the transport minister Chris Grayling that the government has backed a third Heathrow runway.
Ray Puddifoot, leader of Hillingdon Council, said: “It is unthinkable that any government could allow such a terrible decision to go ahead.
“We will continue to fight the expansion of Heathrow in the courts with other councils.”
Simon Dudley, leader of Maidenhead and Windsor Council, told PF that the councils “have been analysing the situation over an extensive period of time” and will “analyse whether or not the government is vulnerable to a legal challenge here.”
Dudley said: “The government’s very material weakness on this is air quality.
“It’s lost three air quality cases in the high courts recently – it doesn’t have a plan, so I think air quality is the Achilles heel.”
Previous legal action against a third runway at Heathrow has been costly for the councils involved – Maidenhead and Windsor, Hillingdon, Wandsworth and Richmond – but Dudley insisted the expense was worthwhile.
“We always want to spend council money wisely, but when you are looking to protect people from adverse affects on their health then, clearly, that is one of the things local authorities should be doing,” he said.
Grayling told the Commons that the Airports National Policy Statement “signals our commitment to securing global connectivity, creating tens of thousands of local jobs and apprenticeships, and boosting our economy for future generations.”
He acknowledged that there were concerns about the creation of a new runway, and said that taking such a decision was “never easy”.
The transport minister, who has faced heavy criticism recently due to rail chaos, said the decision was taken in the national interest and was based on detailed evidence.
Grayling has promised £2.6bn in compensation for residents and noise-abatement measures, including £740m to insulate homes, schools and community buildings against noise.
The transport select committee previously raised concerns about the effect expansion would have on noise and air quality.
The committee’s chair Lilian Greenwood said: “These plans have been more than 20 years in the making. The fallout from the decision will last much longer. It is important we get this right.”
