High Court hearing for legal challenge against Gatwick Airport second runway

The judicial review claim is being brought by campaign and environment group Communities Against Gatwick Noise Emissions (CAGNE), and opposes Transport Secretary Heidi Alexander’s decision to grant development consent for the project.  

In the hearing, CAGNE’s arguments will include that the climate change impacts of the extra runway have not been properly assessed.  

The planned expansion would see the repurposing of Gatwick Airport’s emergency runway for use as a second operational runway. The extra capacity is expected to lead to more than 100,000 more flights per year.  

Plans for the project were submitted in July 2023 and following an examination period, were granted development consent by the Transport Secretary in September 2025.  

CAGNE says that this decision was flawed, arguing that there are numerous gaps in the environmental assessment of the airport expansion. These include a failure to adequately assess inbound flight emissions, the climate impact of non-carbon dioxide emissions, the handling of additional sewage, and noise pollution.  

The group also argues that the second runway plans rely too heavily on the UK’s Jet Zero Strategy (JZS), which assumes ambitious improvements in the aviation industry in areas such as fuel efficiency.  

CAGNE says that the planned expansion should not overly rely on the JZS for assessing emissions, labelling the strategy's ambitions as “not necessarily realistic”.  

In October 2025, CAGNE sent a pre-action protocol letter to the Transport Secretary calling for development consent to be withdrawn. 

Development consent was not withdrawn, and the following month CAGNE filed a judicial review claim challenging Ms Alexander’s decision to grant development consent. 

The case will now be heard in a rolled-up hearing next week on the following grounds: 

• Flawed approach to calculating the significance of greenhouse gas emissions and/or failure to provide adequate reasons.  
• Error of law in the treatment of greenhouse gas emissions from international inbound flights.  
• Error of law in the treatment of non-carbon dioxide emissions.   
• Failure to take into account material risks in relation to the Jet Zero Strategy (JZS) and/or comply with the duty to make enquiries and/or irrational approach to the JZS.   
• Unlawful failure to weigh noise harms in the planning balance.   
• Unlawful requirement concerning wastewater treatment. 

CAGNE’s case will be heard alongside another judicial review claim brought by local resident Peter Barclay, also contesting the decision to grant development consent. 

Sally Pavey, chair of CAGNE, said: 

“The Transport Secretary seems to have taken a rose-tinted view of this planning application whilst the planning inspectorates recommended refusal. 

“It is unrealistic to expect local authorities, and the taxpayer, to continue to meet the infrastructure costs of airport expansion and the loss of wellbeing due to ever increasing noise. Gatwick exports sterling out of the UK purse for leisure whilst endangering the planet further by ignoring the lack of accurate decarbonising by this sector. CAGNE is proud to represent residents of Sussex, Surrey, Kent and beyond in calling for this application for a new runway to be overruled.” 

Leigh Day solicitor Julia Eriksen, who represents CAGNE, said: 

“The addition of a second operating runway at Gatwick Airport will inevitably have substantial climate impacts, the assessment of which our client, CAGNE, argues is legally flawed. The group will argue that development consent for the expansion should not have been granted, given what they feel are a number of gaps in the planning application and assessment of environmental effects. CAGNE look forward to presenting their claim  before a judge in the High Court.”