The UK’s highest court overturned a previous victory for campaigners in February, which had said the National Policy Statement – the government’s document which gave the runway the green light – was drawn up unlawfully.
A panel of five Supreme Court justices heard the challenge, brought by Heathrow Airport Ltd. The airport’s lawyers said its owners still want to go ahead with the expansion despite the coronavirus pandemic.
But they said that construction could not be completed until 2030 at the earliest, even if work begins in the near future.
The Court of Appeal had ruled in February that the National Policy Statement was drawn up unlawfully because bungling Transport Secretary Chris Grayling didn’t take into account the Paris Agreement on climate change.
The UN’s Paris Agreement, which came into force in November 2016, commits signatories to tackling climate change by taking measures to limit global warming to well below 2C.
The Court of Appeal ordered that the NPS was dropped and rewritten. But that ruling was overturned today.
Supreme Court Justice Lord Sales said the Government’s decision was lawful and there was “no obligation” to discuss the Paris Agreement separately in the ANPS.
Despite today’s victory by the vast London airport, campaigners have insisted the fight is not over and the runway may never be built.
John Stewart, who chairs anti-Heathrow expansion group Hacan, said: “Despite this verdict, there remains real doubt about whether the third runway will ever see the light of day.
“Recovery is all that is on Heathrow’s mind right now. Flight numbers are down nearly 90%. The airport’s expansion team has long since been disbanded.
“A third runway remains no more than a distant and uncertain prospect.”
Paul McGuinness, who chairs the No 3rd Runway Coalition, said the ruling “may yet prove irrelevant with so much having changed since Heathrow was recommended for expansion”.
He went on: “The assessments on air quality, noise, carbon and the economics are all out of date, with chunks having already been exposed as inadequate.
“Moreover, the Government’s climate advisers say expanding Heathrow in the prosperous South East would mean restrictions on aviation in less advantaged regions. Such a drift in policy is not compatible with today’s levelling up agenda.
“Heathrow’s campaign is mired in economic self-interest and, rather than allowing it to drift on interminably, we would urge the Government to look to the country’s wider interests and drop the Airports National Policy Statement altogether.”
Caroline Russell, Green Party transport spokesperson and London Assembly member, said: “Heathrow expansion would be a disaster for London.
“It already disrupts the health and quality of life of more than three times as many people as any other airport in Europe.
“Neither Londoners nor the planet can afford to see its size and damage grow.”
Justine Bayley, a resident of Harmondsworth, who faces having to leave her home if the third runway is built, said: “I’m disappointed as I’d hoped sense would prevail and the Court of Appeal’s judgment would be upheld.
“Heathrow may have won this particular ruling, but there are many more hurdles in their way before they have final approval to build a third runway.