Legal challenge against second Gatwick runway begins

Campaign group Communities Against Gatwick Noise Emissions (CAGNE) has put forward a legal challenge opposing the construction of a second operating runway at Gatwick Airport.  

In a pre-action protocol letter to Transport Secretary Heidi Alexander, marking the first step towards a potential judicial review challenge, CAGNE argues that the decision to grant development consent was flawed.  

The group says that there was a failure to properly assess greenhouse gas emissions from the project and its impact on climate change and calls on the Transport Secretary to overturn her decision.  

Plans for the second runway at Gatwick were submitted by the airport for consideration in July 2023. The plans involve moving and repurposing the airport’s current back-up runway, allowing it to operate simultaneously alongside the main runway.  

After an examination period from August 2023 to August 2024, plans for this second runway were granted development consent by the Transport Secretary in September 2025.  

It is estimated that the expansion will result in more than 100,000 extra flights per year by the late 2030s. 

Plans for the expansion make emissions calculations based on the Jet Zero Strategy (JZS). The JZS sets out scenarios for the development of the aviation industry based on marked improvements in areas such as fuel efficiency, beyond current technology. 

CAGNE says that the JZS should not be relied upon for assessing emissions describing it as “highly ambitious and not necessarily realistic”.  

The group also argues that there are gaps in the environmental assessment of the runway expansion as it does not include an evaluation of inbound flight emissions, non-carbon dioxide emissions, and well-to-tank emissions associated with the manufacture and transport of fuel. 

CAGNE claims that the planning process failed to properly factor in additional noise pollution and impact on air quality, as well as the cumulative impact of the development on the environment along with the proposed extra runway at Heathrow Airport. 

In its letter to the Transport Secretary, CAGNE lists its proposed grounds of challenge as: 

• Failure to reach an adequately reasoned conclusion on significance of climate change impacts. 
• Failure lawfully to assess greenhouse gas emissions contrary to the EIA Regulations  
• Breach of Environmental Impact Assessment (EIA) Regulations through failing to assess non-carbon dioxide emissions. 
• Breach of EIA Regulations through failing to assess cumulative effects with Heathrow. 
• Breach of EIA Regulations and/or unlawful failure to give reasons for conclusions on air quality impacts from road traffic. 
• Breach of EIA Regulations and/or procedural unfairness in reliance on a report estimating operational noise levels. 
• Unlawful reliance on the Jet Zero Strategy High Ambition Scenario. 
• Error of law in relying extensively on the JZS, if the Court of Appeal finds that it is unlawful. 
• Failure to give adequate reasons for affording the Proposed Development policy support from the ‘Making best use of existing runways’ (MBU) policy. 
• Unlawful failure to weigh noise harms in the planning balance. 
• Unlawful requirement concerning wastewater treatment. 

CAGNE is urging the Transport Secretary to revoke development consent and says it may bring a judicial review challenge if this does not happen. 

Sally Pavey, chair of CAGNE, said: 

“We must question a decision that allows big business to impact the foundations of our planning process. Increased low-cost flights export sterling from the UK economy, and place unsustainable burdens on the inadequate infrastructure. The long-term effects of increased emissions on future generations and the planet cannot be addressed with aviation profits. This decision to allow Gatwick's expansion makes no economic or ethical sense, so we must challenge it through the legal process.” 

Leigh Day solicitor Rowan Smith, who represents CAGNE, said: 

“The addition of a new operating runway at Gatwick Airport will result in a large amount of extra activity and air traffic at the airport. Our client says that the impact of this has not been adequately assessed or considered in the decision to grant development consent, with gaps and flaws in a number of key areas. CAGNE is calling on the Transport Secretary to agree to the overturning of development consent and is looking at the possibility of bringing a judicial review challenge if that request is refused.”  CAGNE is crowdfunding to support its legal claim. 

CAGNE is crowdfunding to support its legal claim.