Barclay v Transport Secretary: High Court dismisses challenges to Gatwick Airport's Northern Runway Project DCO

The Planning Court has dismissed two judicial review claims challenging the Secretary of State for Transport's decision to grant a Development Consent Order for Gatwick Airport's Northern Runway Project, upholding the lawfulness of the consent on all grounds raised.

Mr Justice Mould delivered judgement on 23 June 2026 in Peter Barclay and Anor v Secretary of State for Transport [2026] EWHC 1556 (Admin), rejecting challenges brought by local resident Peter Barclay and Communities Against Gatwick Noise Emissions (CAGNE) against the DCO made on 21 September 2025.

The Northern Runway Project

The DCO authorises development enabling dual runway operations at Gatwick Airport by repositioning the existing northern runway approximately 12 metres northward and lifting historical restrictions on its simultaneous use with the main runway. The northern runway currently functions as a parallel taxiway except when the main runway is unavailable. The project also encompasses upgrades to surface access infrastructure, terminals, and airport facilities.

The Examining Authority had initially recommended refusal under GAL's original draft DCO, but recommended approval under an alternative DCO incorporating enhanced operational controls. The Secretary of State agreed with the latter recommendation and made the DCO accordingly.

The ANPS and policy framework

Mr Barclay argued that the Secretary of State had misinterpreted the Airports National Policy Statement, contending it contained broader policy hostility to Gatwick expansion. Mould J rejected that contention. ANPS paragraph 1.39, read with the contemporaneous "Making Best Use of Existing Runways" policy, expressed clear support for airports beyond Heathrow making best use of existing runways. Paragraphs 3.18 and 3.19 of the ANPS addressed only the comparative assessment of a new Gatwick second runway against the Heathrow Northwest Runway scheme and did not bear on intensification of existing runway use.

Mould J also rejected the submission that the Secretary of State had failed to promote the statutory objectives of the Planning Act 2008 and Climate Change Act 2008 by proceeding against an out-of-date NPS. The court held she acted lawfully in proceeding under section 105 of the Planning Act 2008, treating both the ANPS and the Carbon Budget Delivery Plan as important and relevant considerations under that framework.

GHG emissions, inbound flights and non-CO2

CAGNE's principal climate-related grounds were dismissed in their entirety. On the significance of GHG emissions, the court found no inherent contradiction in the Secretary of State concluding simultaneously that the proposed development's effects were significant under the IEMA guidance's moderate adverse criteria, while also finding they would not materially impact the government's ability to meet its carbon reduction targets under ANPS paragraph 5.82. Those two tests operate independently.

On downstream emissions from inbound international flights, the court applied the Supreme Court's reasoning in Finch v Surrey County Council [2024] UKSC to hold that the Secretary of State's inability to carry out a meaningful quantitative assessment in the absence of an appropriate international benchmark was rational and lawful. The court similarly upheld the qualitative approach to non-CO2 emissions, no scientific consensus on a reliable quantitative methodology having emerged by the time of the decision.

The challenge to the Secretary of State's reliance on the Jet Zero Strategy high ambition scenario was also rejected. Following the Court of Appeal in R (Global Feedback) v Secretary of State for Energy Security and Net Zero [2024], the court held it was not for a DCO decision-maker to interrogate delivery risks of the JZS; that function belongs to the Secretary of State for Energy Security and Net Zero under the Climate Change Act 2008.

The attribution of neutral weight to noise and vibration in the overall planning balance was upheld, as was the requirement addressing wastewater treatment capacity in schedule 2 to the DCO, which the court found rational and sufficient to address the relevant risk.

Alex Goodman KC and Gethin Thomas (instructed by Goodenough Ring Solicitors) for the First Claimant. Estelle Dehon KC, Ruchi Parekh, Odette Chalaby and Lois Lane (instructed by Leigh Day) for the Second Claimant. Nigel Pleming KC, Rose Grogan and Daniel Kozelko (instructed by Government Legal Department) for the Defendant. James Strachan KC and Victoria Hutton (instructed by Herbert Smith Freehills Kramer) for the Interested Party.