Environmental group seek to appeal High Court ruling on Gatwick Airport second runway

In Peter Barclay v Secretary of State for Transport Communities Against Gatwick Noise Emissions v Secretary of State for Transport [2026] EWHC 1556 (Admin), Mr Justice Mould concluded that the Secretary of State for Transport (SST) did not carry out a legally flawed noise impact assessment, nor did the SST misinterpret or fail to apply national policy for the management and mitigation of aircraft noise.

The claimants were Peter Barclay, a local resident and Chair of the Gatwick Area Conservation Campaign (GACC), and Communities Against Gatwick Noise Emissions (CAGNE).

In the judgment handed down last month (23 June), Mr Justice Mould granted permission on grounds 1 and 4 of Mr Barclay's claim but rejected both grounds. He refused permission on grounds 2, 3 and 5 of Mr Barclay's claim.

The judge granted permission on grounds 1, 6 and 7 of CAGNE's claim but rejected each of the grounds. He refused permission on CAGNE's grounds 2, 3 and 4. CAGNE withdrew ground 5 of its claim.

Both claims were therefore dismissed.

In an application to the Court of Appeal, CAGNE argues that the High Court was wrong in law on the following grounds:

• The treatment of the project’s greenhouse gas emissions: “The judgment failed to resolve an irrational contradiction in the government’s decision. The development was found to have a significant adverse effect on the climate and to be incompatible with the UK’s net zero trajectory under environmental assessment guidance, but it was simultaneously concluded that it would not materially affect the government’s ability to meet its climate targets.”
• Non-CO2 aviation emissions: “Both the Secretary of State and the High Court accepted these emissions were an environmental effect of the proposed development but wrongly concluded that no quantitative assessment was legally required, despite the availability of methodologies for assessing their climate impacts.”
• Reliance placed on the government’s Jet Zero Strategy: “The Secretary of State failed to take account of evidence concerning delivery risks associated with the strategy or, alternatively, failed to make reasonable enquiries about those risks before relying upon it when approving the project.”
• Wastewater infrastructure: “The planning requirements imposed by the government do not lawfully ensure that adequate wastewater treatment infrastructure will be operational before expansion takes place and therefore fail to address the environmental risks they were intended to prevent.”

The Court of Appeal will now consider CAGNE’s application for permission to appeal.

Leigh Day solicitor Julia Eriksen, who represents CAGNE, said: "Following careful consideration of the High Court’s judgment, our client has applied for permission to appeal because it believes there are important errors of law which should be considered by the Court of Appeal. This case raises significant issues about how the climate impacts of major infrastructure projects are assessed, the approach taken to aviation emissions, and the legal standards that apply when nationally significant infrastructure projects are approved.

"Our client remains concerned that the environmental effects of the proposed expansion have not been assessed or addressed in accordance with the law and looks forward to the Court of Appeal considering the application." 

CAGNE’s application to appeal will be heard alongside an appeal brought by Peter Barclay of GACC, who is also contesting the decision to grant development consent.

According to Goodenough Ring Solicitors, Peter Barclay’s appeal focuses on two grounds of challenge:

• The failure of the judge to grapple with both the misinterpretation of government policy by the Secretary of State; and
• The “fundamental flaws” in Gatwick Airport’s economic case, specifically the flaws in London Gatwick Airport Limited’s business passenger forecast relied upon by the Secretary of State in her assessment of national economic benefit.

Goodenough Ring Solicitors said: “The appeal will proceed under new expedited procedures for nationally significant infrastructure challenges. Those procedures require appellants to file an application for permission to appeal to the Court of Appeal within seven days of the decision of the High Court. A decision on permission should be made within four weeks of the filing of the appellant’s notice. If permission is granted, a hearing should take place within four months of the date of the appellant’s notice.”

Peter Barclay of GACC is represented by Goodenough Ring Solicitors, who have instructed Alex Goodman KC (Landmark Chambers) and Gethin Thomas (39 Essex Chambers).

Lottie Winson