Plans for a third runway at Heathrow have been given a major boost after the airport's owner won a Supreme Court challenge.

Heathrow Airport Ltd successfully overturned an earlier ruling that the Government had failed to take account of its own climate commitments when it approved the scheme.

Three leading judges concluded in February that former transport secretary Chris Grayling failed to take account of the Government's commitments to tackling climate change when setting out support for the project in an Airports National Policy Statement (ANPS).

They said the ANPS was unlawful because Mr Grayling failed to take account of the Government's commitment to the Paris Agreement - which commits signatories to tackling climate change by taking measures to limit global warming to well below 2C.

Heathrow Airport Ltd, which owns and operates the airport, challenged that ruling at a two-day hearing before a panel of five justices in October.

Giving a summary of the Supreme Court's ruling on Wednesday (Dec 15), Lord Sales said Mr Grayling's decision was lawful and he was under "no obligation" to discuss the Paris Agreement separately in the ANPS.

The airport's challenge was opposed by environmental charities Friends of the Earth and Plan B Earth - both of which argued that the appeal should be dismissed by the Supreme Court.

The Court of Appeal considered the case following a challenge by a group of councils in London affected by the expansion, environmental charities including Greenpeace, Friends of the Earth and Plan B Earth, and London mayor Sadiq Khan.

The effect of the ruling, which overturned a previous High Court decision made in May last year, was that current Transport Secretary Grant Shapps would have to review the ANPS to ensure it accords with the commitments on climate change.

The Government did not oppose the court's declaration that the ANPS was unlawful and did not seek permission to appeal to the Supreme Court.

Parmjit Dhanda, Executive Director of Back Heathrow, a campaign group supporting a new runway at Heathrow, said:

“The Supreme Court judgement comes at a crunch time for the UK’s struggling economy. The go-ahead for a new runway will give hope for new jobs and a post Covid recovery. Else we face the loss of much needed trading opportunities, at a time of growing Brexit uncertainty.

Back Heathrow says expansion will bring 180,000 new jobs and 10,000 apprenticeships to the UK.

However, Paul McGuinness, Chair of the No 3rd Runway Coalition, said the ruling may not make a significant difference. 

He said: "This decision will disappoint a very large number of people. However, it may yet prove irrelevant with so much having changed since Heathrow was recommended for expansion. 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. And 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."