Campaigners lose High Court challenges over expansion of Gatwick Airport

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.

Mr Justice Mould noted that currently, Gatwick Airport operates with a single main runway and two terminals.

In September 2025, a Development Consent Order (DCO) was granted by the SST, authorising development which will enable dual runway operations at the airport through altering the existing northern runway.

Mr Justice Mould said: “The proposed development is a nationally significant infrastructure project ["NSIP"] as defined in section 14 of the Planning Act 2008.”

Gatwick Airport Limited (GAL) made the application for development consent on 6 July 2023. The application was accepted for examination on 3 August 2023. The examination began on 27 February 2024 and was completed on 27 August 2024.

In a report dated 27 November 2024, the Examining Authority (ExA) concluded that under the draft DCO submitted for approval by GAL, moderate levels of harm would be caused to matters of greenhouse gas (GHG) emissions, traffic and transport, and noise, with some harm to matters relating to the water environment and health and well-being.

The ExA concluded that the harm caused by the proposed development would outweigh its benefits. The ExA recommended refusal of the application for development consent on the basis of the draft DCO submitted by GAL.

However, the ExA went on to recommend an alternative DCO which introduced a wide range of detailed planning controls on the operation of the proposed development, such that harm levels would be reduced in matters of traffic and transport; and controlled in relation to noise, the water environment and health and well-being.

On the basis of the alternative DCO, the ExA concluded that the benefits of the proposed development would now outweigh harm and so recommended approval.

On 27 February 2025, the SST issued a letter ["the MDL"] stating that she was minded to agree with the ExA that development consent could be granted on the basis of their recommended alternative DCO. However, the SST considered that she was not yet in a position to make a final decision.

Instead, the SST invited GAL to respond on certain matters raised in the MDL.

Following the completion of that procedure, on 21 September 2025, the SST issued her decision letter (the DL) granting development consent for the proposed development.

The DCO authorising the Northern Runway Project in the terms concluded upon by the SST was made on the same date.

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

GACC was established in 1968 and seeks to protect and improve the environment in the local area around Gatwick Airport.

CAGNE is a community group formed in February 2014 to address issues in relation to Gatwick Airport, particularly noise impacts and environmental harm.

Mr Barclay, GACC and CAGNE all participated in the examination process and later consultation following publication of the Examining Authority’s report.

Mr Barclay advanced the following five grounds of challenge to the SST's decision to grant development consent for the proposed development:

1. The SST failed properly to understand the Airports National Policy Statement (June 2018) ["the ANPS"] and/or failed to have regard to relevant policy of the ANPS concerning expansion of Gatwick Airport.
2. In granting development consent pursuant to section 114 of the 2008 Act, the SST was obliged but failed to exercise her power so as to promote the policies and objects of the statutory scheme.
3. In making the DCO the SST acted in breach of certain provisions of the Infrastructure Planning (Environmental Impact Assessment) Regulations 2017 ["the EIA Regulations"] and/or failed to reach conclusions on the DCO and/or the adequacy of the environmental impact assessment ["EIA"] for the proposed development in a procedurally rational manner; or alternatively, the SST's conclusions were Wednesbury unreasonable.
4. The SST's consideration of need and economic benefits was procedurally irrational and/or Wednesbury unreasonable.
5. The SST erred in her interpretation of the Aviation Policy Framework (March 2013) ["the APF"] and ANPS policies governing aviation noise and/or in any event, reached irrational conclusions on noise.

CAGNE advanced the following six grounds of challenge:

1. The SST took an irrational approach to the significance of GHG emissions and/or failed to give adequate reasons for her approach to that issue.
2. The SST erred in law in her consideration of GHG emissions from international inbound flights under the EIA Regulations.
3. The SST erred in law in her consideration of non-carbon dioxide (CO2) emissions under the EIA Regulations.
4. The SST failed to take into account material risks to the Jet Zero Strategy (July 2022) ["JZS"] and/or to comply with her Tameside duty of reasonable inquiry and/or took an irrational approach to the JZS.
5. The SST unlawfully failed to weigh harmful noise impacts in the planning balance.
6. The SST imposed an unlawful requirement in schedule 2 to the DCO in respect of Work No 44 (wastewater treatment works).

Considering the case, Mr Justice Mould applied the principles for judicial review of a DCO decision as summarised in R (Save Stonehenge World Heritage Site Limited) v Secretary of State for Transport [2022] PTSR 74.

In relation to the Climate Change Act 2008, he referred to R (Global Feedback Limited) v Secretary of State for Environment, Food and Rural Affairs [2024] 1 WLR 2923.

On the approach to judicial review of environmental impact assessment, he referred to R (Friends of the Earth) v Heathrow Airport Limited [2021] PTSR 190 and R (Finch) v Surrey County Council [2024] PTSR 988.

Looking at the national policy framework, Mr Justice Mould concluded that the SST was correct to base her decision on the policy support given to making best use of the existing runways at airports in London and the South East. He also found the SST’s decision to be in accordance with the statutory purposes of the Planning Act 2008.

He added: “The SST considered both the need for and the socio-economic effects of the proposed development to be important and relevant considerations in her decision on GAL's application. Both were raised by policy and considered by the SST within the policy framework set by the APF and ANPS. It is beyond argument that the SST had regard to those considerations.”

Meanwhile, Mr Justice Mould found that the SST’s approach to assessing the emissions from inbound international flights and non-CO2 emissions was “lawful and reasonable”.

Other challenges to the SST’s assessment of the environmental effects of the project on climate were also rejected.

Finally, Mr Justice Mould found that the 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.

He found no legal flaw in the SST’s decision to impose requirement 31(9) of the DCO to enable the effective management of wastewater from future operation of the expanded airport.

Mr Justice Mould concluded: “I grant permission on grounds (1) and (4) of Mr Barclay's claim but reject both grounds. I refuse permission on grounds (2), (3) and (5) of Mr Barclay's claim.

“I grant permission on grounds (1), (6) and (7) of CAGNE's claim but reject each of those grounds. I refuse permission on CAGNE's grounds (2), (3) and (4). CAGNE withdrew ground (5) of its claim. The overall outcome is that both claims are dismissed.”

A London Gatwick spokesperson said: “We are pleased with today’s High Court ruling to uphold the Government’s careful decision to grant planning approval for our Northern Runway Project. Our exciting plans will deliver significant business, tourism and trade benefits for the UK, including 14,000 new jobs and a £1bn boost to the economy every year. This is a victory for common sense. We now look forward to turning our plans into reality and will announce further details in due course.”

CAGNE said it would "not accept this ruling as the final word. Our legal team will now consider an appeal, and we will continue to stand up for the communities who will be forced to live with the consequences of this expansion.

“CAGNE are obviously disappointed by [the] ruling. Communities across Sussex, Surrey and Kent helped fund this legal action because they have grave and legitimate concerns about the proposed expansion: the lack of airport funding for essential infrastructure, the absence of proper investment in sewerage treatment, the increased noise burden on local residents, worsening air quality, and the significant rise in CO2 and other harmful emissions.

“Today’s ruling provides no reassurance for those concerns. It does not change the fact that local communities are being asked to carry the consequences while the airport fails to provide the funding needed to protect the people and places affected.”

Peter Barclay said: “Both before and since the DCO was approved by the Secretary of State, the Climate Change Committee, and now the Parliamentary Environmental Audit Committee also, have strongly recommended there should be no airport expansion.

"The expansion decision ignores that advice and the judgment today provides no answer on how outdated National Policy Statements should be addressed. Thus we must continue to challenge the Secretary of States's decision to allow Gatwick to proceed with this highly damaging project."

He added: “The upshot of the judge’s decision seems to be that noise policies are not worth the paper they are written on. They don’t require proper protections in a meaningful timeframe, while airports reap the economic benefits of expansion. This is particularly disappointing given the recent reports published on the harmful impact of noise on communities."

Lottie Winson