The planned expansion of Heathrow airport has suffered another setback, following a challenge by local authorities and campaign groups on environmental grounds.

The Court of Appeal has ruled that the government’s Airports National Policy Statement (ANPS) – which effectively gave the go-ahead for a third runway at Heathrow – was unlawful as it failed “to take into account the Government’s commitment to the provisions of the Paris Agreement on climate change”.

A number of challenges had been brought by several local authorities, the
Mayor of London, Greenpeace, Friends of the Earth and Plan B Earth. Most of these were dismissed, but one key challenge surrounding the Paris Agreement was upheld.

The Court of Appeal said that the fact that the Paris Agreement had not been taken into account by the Secretary of State in the preparation of the ANPS, “and an explanation given as to how it was taken into account”, meant that the statement was “legally fatal” in its present form.

The Mayor of London Sadiq Khan welcomed the ruling, tweeting:

“This is huge. I’m delighted that the Court of Appeal has recognised that the Government cannot ignore its climate change responsibilities. I will continue to stand up for Londoners’ concerns by doing everything I can to stop the Heathrow expansion.”

Meanwhile Heathrow announced its intention to appeal against the decision, stating:

““The court of appeal dismissed all appeals against the government – including on ‘noise’ and ‘air quality’ – apart from one which is eminently fixable.

“We will appeal to the supreme court on this one issue and are confident that we will be successful. Expanding Heathrow, Britain’s biggest port and only hub, is essential to achieving the prime minister’s vision of Global Britain. We will get it done the right way.”

The Court of Appeal stressed that its task had not been to examine “the political debate and controversy to which the prospect of a third runway being constructed at Heathrow has given rise”, adding that “That is none of the court’s business”.

“Our task therefore – and our decision – does not touch the substance of the policy embodied in the ANPS,” said the court. “In particular, our decision is not concerned with the merits of expanding Heathrow by adding a third runway, or of any alternative project, or of doing nothing at all to increase the United Kingdom’s aviation capacity. Those matters are the Government’s responsibility and the Government’s alone.”