Campaigners trying to block Heathrow expansion are set to have their legal challenge over controversial plans for a third runway heard by the Court of Appeal.

A group of councils, residents, environmental charities and Mayor of London Sadiq Khan brought four separate judicial reviews of the Government’s decision to approve the plans at the High Court in March.

The cases were dismissed by two leading judges in May, but their appeals against that ruling will be heard in London over four days starting on Thursday.

Giving reasons for his decision, which he made based on case documents without a hearing, the judge said: “The importance of the issues raised in these and the related proceedings is obvious.”

The case, against the Department for Transport, is being brought by local authorities and residents in London affected by the expansion, and charities including Greenpeace, Friends Of The Earth and Plan B.

The campaigners claim the Government’s National Policy Statement (NPS) setting out its support for the project failed to properly deal with the impact on air quality, climate change, noise and congestion.

During the two-week High Court hearing, their lawyers argued the plans would effectively create a “new airport” with the capacity of Gatwick and have “severe” consequences for Londoners.

Paul McGuinness, chairman of the No 3rd Runway Coalition, said: “If the unavoidable increases in noise pollution and poorer air quality were not enough, the recent inclusion of a net zero carbon target in the Climate Change Act has tightened the noose around Heathrow expansion even further.

“The Committee on Climate Change has highlighted that demand for aviation must be limited and that a third runway at Heathrow would inevitably mean restrictions on capacity at other airports across the UK.

“It’s now vital for Government to pause plans for Heathrow expansion, to reassess airport capacity strategy for the whole country.”

Jenny Bates, campaigner at Friends of the Earth, said: “Declaring a climate emergency while backing Heathrow’s third runway project shows the climate hypocrisy of our Government.

“Expanding Heathrow would lead to a huge increase in climate-wrecking emissions.

“It’s time the Government is held to account over the third runway, and for it to give some actual thought to go into what a third runway would mean for the planet.

“We need to be cutting down the number of planes in our skies, not giving them a massive daily boost.”

John Sauven, executive director of Greenpeace UK, said: “The Government might be making all the right noises about the climate and nature emergency but they are not doing the right things.

“Heathrow’s third runway is the poster-child for this huge disconnect between official rhetoric and action.

“An enormous expansion of carbon emissions and pollution at the exact moment they agreed to do the opposite is unacceptable.

“The Government needs to curb emissions now by tackling the growth in aviation.”

Tim Crosland, director of Plan B, said: “A policy to expand aviation in the midst of the climate and ecological emergency is a policy to reduce the life chances of the most vulnerable to maximise the temporary convenience of the few.”

The appeals will be heard by Lords Justice Lindblom, Singh and Haddon-Cave, alongside a separate challenge by Heathrow Hub – a consortium with a rival proposal for the airport’s expansion.

Support from Labour MPs helped push through the proposals to expand Europe’s busiest airport with an overwhelming majority of 296 in a Commons vote in June last year.

Then transport secretary Chris Grayling said at the time that the new runway would set a “clear path to our future as a global nation in the post-Brexit world”.

Construction could begin in 2021, with the third runway operational by 2026.