No silent night for LADACAN - court upholds approval for Luton airport expansion

On the 8th day of Christmas (8 December 2025) the High Court dismissed local campaign group LADACAN's (Luton And District Association for the Control of Aircraft Noise) (Claimant’s) crowdfunded judicial review claim against the planned London Luton Airport expansion, ruling against the group on all five of the grounds considered. 

Background

Earlier this year the Secretay of State for Transport (Defendant) granted Luton Rising (which is solely owned by Luton Council) a development consent order (DCO) for the expansion of Luton Airport, despite the Examining Authority’s (ExA’s) clear recommendation to reject the plans because “the public benefits do not outweigh the environmental harm”. The expansion includes construction of a new runway and terminal to further increase capacity from 19 million to 32 million passengers per year by 2043.

Despite the UK Government’s advisory body, the Climate Change Committee, urging the UK Government to stop airport expansion “without a UK-wide passenger capacity management framework” and “unless the carbon intensity of aviation is outperforming the government’s emissions reduction pathway”, the UK Government continues to support expansion plans at Heathrow, Gatwick, London City and Bristol, for their economic growth. This case illustrates the ongoing legal and policy challenges of reconciling the UK’s legally binding net-zero targets with transport and economic planning.

Whilst this is a public law case, there are some points of general interest to commercial lawyers.

Wednesbury unreasonableness

The Supreme Court confirmed in Braganza that the Wednesbury unreasonableness test developed in public law, can also be applied to the exercise of contractual discretion in private law contracts (the “Braganza duty”). 

The Wednesbury irrationality test of whether a consideration is “so obviously material” that a decision-maker must take it into account⁴, was considered in Ground 2. The Claimant argued there was an irrational failure to take account of a material consideration, specifically the views of the ExA for the similar Gatwick Airport expansion. The Gatwick ExA identified the same methodological difficulties with assessing inbound flight emissions against UK carbon budgets, but nonetheless took them into account and concluded that they could push the development towards being a "significant adverse effect in EIA terms". The judge agreed with the Defendant ruling that the high threshold of Wednesbury irrationality required for failing to consider an "obviously material" consideration was not met. The Gatwick ExA was not found to be a mandatory material consideration for the following reasons:

• Gatwick ExA’s views were merely recommendations and were rejected by the decision-maker;

• Gatwick is a larger capacity airport so the resulting emissions were quantitively different and therefore not comparable;

• Gatwick ExA’s reasoning was internally inconsistent and flawed as it was not possible to carry out a meaningful assessment of inbound emissions against a relevant benchmark; and

• Regardless, the Defendant concluded inbound flight emissions (even in combination with the total greenhouse gas emissions) were not of a scale to justify changing their conclusions on significance and refusing consent.

Use of benchmarks in a contract 

The use of benchmarks can be essential in contracts that require assessment against a standard. However, this case demonstrates the importance of choosing and clearly specifying a benchmark that allows for meaningful contextualisation and compares like-with-like. Otherwise parties risk certain standards being disregarded due to scientific uncertainty, or being qualitatively assessed.

Ground 2 above showed the court rejecting comparing calculated emissions against benchmarks that explicitly exclude certain factors, like inbound flights. The question of how to go about assessing significance when there is no accepted benchmark was also considered in Ground 3.

In Ground 3 the Claimant argued that omitting non-CO₂ emissions (such as nitrogen oxides and water vapour) from the Environmental Impact Assessment (EIA) breached the EIA Regulations² requiring a developer to “identify, describe and assess” the direct and indirect significant effects of a proposed development and the precautionary principle. The court found non-CO₂ effects had been considered, but on a qualitative and high-level basis because of significant scientific uncertainty about the scale of their effects, and the lack of accepted methodology or benchmark for quantification. The judge said there is no legal obligation to attempt to quantify non-CO₂ emissions and that assessing their significance “in an appropriate manner, in light of each individual case” (Regulation 5(2) EIA Regulations) is a matter for the decision-maker’s judgment. The Defendant made a legitimate evaluative judgment that quantification was not appropriate in this specific case, which was consistent with previous legal findings in the Bristol Airport case³.

Use of comparators to assess damages 

Courts often use comparators to assess what would be a fair royalty payment in licensing disputes. Actual market transactions for the same or comparable intellectual property will be used, with adjustments to account for the specific circumstances at issue.

In Ground 5 the judge considered whether the Defendant gave adequate reasons for finding that a £250,000 fund for conservation or enhancement projects was sufficient to meet section 85(A1) of the Countryside and Rights of Way Act 2000 (CROW Act), which mandates the conservation and enhancement of areas of outstanding natural beauty. Luton Rising proposed this sum in response to the ExA’s finding that the CROW Act duty had not been complied with. They calculated the figure using the closest comparator of the £3.75 million “Mend the Gap” fund for the area impacted by the Great Western Railway electrification scheme, scaled to represent the size of the area affected by the increase in overflying planes.

The judge found that the Defendant’s conclusion that the £250,000 was a "reasonable and proportionate contribution" was based on the Defendant’s consideration of the effects of the development. The duty to give reasons does not require a detailed explanation of every step and there is no heightened standard of reasons where the Secretary of State disagrees with a recommendation from a planning inspector. Hence the Defendant’s reasons met the ordinary standard of reasons in public law decisions of being adequate and intelligible.⁴

Checking it twice?

LADACAN are currently considering whether to appeal the decision and a further sixth ground of challenge is currently stayed pending the outcome of a separate challenge to the legality of the Government’s Jet Zero Strategy. Therefore, we can expect further clarification on the treatment of aviation emissions in planning decisions in the New Year.