The Supreme Court has ruled that the Government’s plans to expand Heathrow Airport were lawful, paving the way for a third runway to be built.

Campaigners have slammed today’s decision, which overrules the Court of Appeal’s February ruling that had declared plans unlawful.

Paul McGuinness, Chair of the No 3rd Runway Coalition, 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 The assessments on air quality, noise, carbon and the economics are all out of date, with chunks having already been exposed as inadequate.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.”

February’s ruling was hailed by environmental campaigners and local activists, having declared that then-transport secretary Chris Grayling had not taken into account the Paris Climate Agreement when giving plans for Heathrow’s expansion the go-ahead.

However, in his ruling today, Lord Sales declared that Mr Grayling “did take the Paris Agreement into account” and that he “was not legally required to give it more weight than he decided was appropriate”.

The decision has been met with criticism from local politicians. Green Party London Assembly Member Caroline Russell said via social media that she was “gutted for Londoners” and “gutted for the planet”, while Conservative AM Tony Arbour, who represents South West London, said the Supreme Court’s decision is “deeply disappointing”.

Mr Arbour said: “Heathrow’s grandiose expansion plan would not only damage the environment but also cause misery for the residents of South West London. If it went ahead, Heathrow’s ‘masterplan’ would take thirty years to complete and cause chaos as motorways and rivers are rerouted. That’s why Heathrow expansion is completely unacceptable.”

Luisa Porritt, the Liberal Democrat candidate running to be Mayor of London, also expressed her concern, saying that an expansion of Heathrow Airport “will break our international obligation to tackle climate change”.

Ms Porritt continued: “Airport expansion is the wrong priority for London, which already needs urgent action to improve our air quality. We know this decision will undermine our efforts to limit global warming to 1.5C, and with COP26 taking place in the UK next year it is essential we show international leadership on this issue.”

Meanwhile, a spokesperson for Heathrow Airport said: “This is the right result for the country, which will allow Global Britain to become a reality. Only by expanding the UK’s hub airport can we connect all of Britain to all of the growing markets of the world, helping to create hundreds of thousands of jobs in every nation and region of our country.”

Despite today’s ruling, expansion at Heathrow Airport still faces several obstacles, including opposition from Prime Minister Boris Johnson.