Gatwick’s Northern Runway Project Cleared for Take-off: R (on the application of Barclay) and Another v Secretary of State for Transport and Another [2026] EWHC 1556 (Admin)

Introduction

On Tuesday 23 June 2026 the High Court dismissed two judicial reviews challenging the order made by the Secretary of State for Transport (SST) granting Gatwick Airport Limited (GAL) development consent for a second operational runway at Gatwick Airport (the Northern Runway Project). The judgment can be found here.

Mr Barclay and Communities Against Gatwick Noise Emissions (CAGNE) brought separate challenges, both of which were rejected by Mould J. The judgment gives the green light to what will be only the second airport in the UK to have a second runway, while providing clarity on a range of key legal issues relating to large aviation (and transport) development.

Background

On 21 September 2025 the SST granted the Gatwick Airport (Northern Runway Project) Development Consent Order (SI 2025/10554) (the Order). The Order gave consent, pursuant to the Planning Act 2008 (PA 2008), for the redevelopment of an existing emergency northern runway at Gatwick Airport. Until the Order, that runway was conditioned so that it could not be operated simultaneously with the main runway. Among other things, the Order removes that condition, and permits Gatwick Airport Limited (GAL) to build infrastructure to operate as a dual runway airport. Given the scope of the application, the proposed development is a Nationally Significant Infrastructure Project (NSIP) for the purposes of the PA 2008.

Procedure

Before even the first day of trial, there were some important procedural skirmishes. This claim was brought after changes were introduced to CPR PD 54D following the report of Lord Banner’s “Independent review into legal challenges against Nationally Significant Infrastructure Projects”. As a result, PD 54D para 3.7 directed that any question related to permission would be considered first at an oral hearing (removing the papers stage).

However, instead of proceeding to an oral permission hearing, on 10 December 2025 the judge directed that there would be a rolled-up hearing of the claim beginning 20 January 2026 with a time estimate of four days. That was, seemingly, a level of expedition even beyond that envisaged by the changes to the Practice Direction. The judge central reason for this was the importance of the proposed development nationally (even amongst other NSIPs).

Additionally, there was a procedural dispute in relation to the first Claimant, Mr Barclay. While all parties accepted the claim was an Aarhus Convention claim, and the second Claimant, CAGNE, recognised that it was an unincorporated association and therefore the £10,000 cap would apply, Mr Barclay asserted he should only be subject to a £5,000 cap. That was notwithstanding that Mr Barclay participated in the examination of the Order both as an individual but also as the Chair of the Gatwick Area Conservation Campaign (GACC). The SST and GAL resisted this, and argued that the claim was brought by Mr Barclay on behalf of GACC and therefore the £10,000 cap should apply.

At the CCMC Mr Barclay argued that he was bringing the claim as an individual, that GACC was an unincorporated association, and that GACC could bring a judicial review claim was no answer to this issue as it conflated its legal identity with that of Mr Barclay. SST and GAL pointed to evidence that Mr Barclay, himself and through GACC, had represented the claim as GACC’s. The judge ultimately ordered £10,000 as the cap, concluding that he must look at the reality of the situation in deciding the issue; the evidence pointed to Mr Barclay bringing the claim for GACC.

The case also included an application for specific disclosure by CAGNE, who sought documents relating to the process of producing the Carbon Budget and Growth Delivery Plan (a report under ss.13 and 14 of the Climate Change Act 2008 (CCA 2008), which is the responsibility of the Secretary of State for Energy Security and Net Zero (SSESNZ)). CAGNE sought disclosure of the “Policy Commission Returns” that the Department for Transport (DfT) produced as part of reporting to the Department for Energy Security and Net Zero (DESNZ), as it said that this was relevant to its Ground 4 (concerning delivery risk of government policy). Ultimately, while the judge considered it unlikely that the disclosure was needed for the claim, he took a precautionary approach and ordered disclosure due to the limited time between the date of the CCMC and the trial. That was notwithstanding the SST’s position that the information sought was sensitive policy information that was not relevant to the claim (more on that later…).

Barclay Ground 1 – failure properly to interpret the ANPS

Mr Barclay’s Ground 1 relied on what he asserted was the correct interpretation of the Airports National Policy Statement ((the ANPS), the relevant National Policy Statement made under the PA 2008), and a policy called “Making Best Use” ((MBU), which was published the same day as the ANPS and specifically addressed encouraging maximal use of existing airport assets). Mr Barclay argued that the ANPS (and MBU) specifically pointed against expansion of Gatwick Airport because that threatened the global hub status of Heathrow Airport, and that this had been recognised by the Airports Commission which reported prior to the ANPS being drafted.

Mould J rejected that interpretation. The Airports Commission (and text in the ANPS and MBU) simply recognised that Heathrow was already at capacity, and Gatwick was at capacity at peak times. That this was the case did not mean that the policy on making best use sought to exclude Gatwick, but rather it recognised that Gatwick was unlikely to offer much by way of further capacity. This was a distinct question to that analysed by the Airports Commission and Chapter 3 of the ANPS, which instead addressed the location for a new runway in the South East of England. A preference for a third runway at Heathrow did not preclude any intensification of the use of Gatwick. In any event, the policy on making best use specifically envisaged developers demonstrating a need additional to and different from the need met by the Northwest Runway at Heathrow. That is what happened here.

The judge gave permission on this ground, but refused the ground on the merits.

Barclay Ground 2 – failure to promote the policy and objectives of the statutory scheme

Mr Barclay’s Ground 2 asserted that the SST had failed to promote the policies of the PA 2008 and the CCA 2008, each of which had the common objective of mitigating climate change by reducing greenhouse gas (GHG) emissions. In essence, it was said that a decision on the Order had to be taken both in the framework of the PA 2008 and ANPS, but also separately in accordance with the framework for meeting net zero in the CCA 2008. Mr Barclay argued that this particularly mattered because there had been material changes to the climate policy landscape subject to the ANPS being published. That included the 2019 amendment to introduce the net zero target. Thus, the ANPS was out of date.

The judge began by noting that it was unchallenged that the airfield component of the Proposed Development was one for which there was no NPS which had effect under s.104. Under s.105 it was a matter for the SST to determine what was “important and relevant” to her decision. She considered that the ANPS was important and relevant under s.105: it was an NPS which addressed large airport development which had neither been withdrawn nor suspended under the specific provisions of the 2008 Act. The SST specifically considered whether the ANPS was out of date, and took that consideration into account when applying the ANPS. She also took into account the Carbon Budget Delivery Plan which, while found unlawful (in separate proceedings in 2025), had not been quashed and remained the relevant ss.13 and 14 CCA 2008 plan. The decision to apply the ANPS in that context could not be said to be irrational.

The judge also noted that Mr Barclay’s submissions did not provide an answer to the question ‘what should the SST do?’. GAL chose the timing of its application and the SST was obliged to determine it in a timely way (s.107 PA 2008). The SST could not simply pause and wait for a new ANPS.

The judge refused permission to apply for judicial review on this ground.

Barclay Ground 4 – need and economic benefits

This ground was based on Mr Barclay’s criticisms of a National Economic Impact Assessment (NEIA) produced for GAL’s application. In particular, it was argued that the assessment produced by GAL failed to address flaws that had been identified from the outset of the examination about the value of benefits to business passengers (who were not price sensitive), and failed to consider whether business passengers were new or just displaced from other airports (including Heathrow).

The judge rejected this argument. He concluded that the benefits that the SST considered justified the proposed development were not primarily founded upon or justified by an estimation of the growth of business passengers. Rather, the focus was on (among other things) the low cost carriers which dominated Gatwick and contrasted the main sources of traffic at Heathrow. That was a need which was additional to and different from Heathrow. As to the socio-economic assessment, the judge noted the detailed review conducted by the Examining Authority and the SST. The SST had identified that GACC considered GAL had overstated the level of economic wealth benefit, and the uncertainties in the economic assessment. However, the STT had lawfully concluded there would be economic benefits, particularly focusing on employment effects and the comprehensive Employment, Skills and Business Strategy. The NEIA had not been relied upon. There is no requirement to refer to each and every material consideration in law, and the approach to interpreting planning appeal decisions (which directs that decisions should be read fairly and not with undue rigour) should be applied here. The standard was met, and sufficient intelligible and adequate reasons were given without a gap in logic.

The judge gave permission on this ground, but refused the ground on the merits.

CAGNE Grounds 1-3, Barclay Ground 3 – GHG emissions

Significance of emissions

CAGNE argued that there was a demonstrable flaw in the reasoning of the SST on the significance of GHG emissions. Applying IEMA (now ISEP) guidance, the SST concluded that the proposed development “will fall short of fully contributing to the UK’s trajectory towards net zero” and concluded that there would be a “moderate adverse effects on the environment, which were significant”. CAGNE argue that the subsequent conclusion that the proposed development is “compatible with [the Jet Zero Strategy (JZS)], can be managed within the government’s overall strategy for meeting net zero and relevant carbon budgets and accordingly will not have a material impact on the UK’s ability to meet its carbon reduction targets” could not be reconciled with those earlier conclusions.

The judge began by noting that planning decision letters must be read fairly and as a whole. He noted that the significance of emissions question is distinct to whether the emissions are so significant as to have a material impact on the meeting of carbon reduction targets. The first question concerns the EIA Regulations, the second the test in para 5.82 of ANPS. On the first issue the SST concluded that the effects of the proposed development are significant, but were not major (instead being moderate adverse). However, on the second, the SST concluded that the GHG emissions increase will be only 0.657% of any one carbon budget, the proposed development is compatible with JZS, and the ability exists to manage the proposed development within the overall strategy for net zero anyway. Those questions are not the same; the materiality of the effect addressed in the second question is important. Para 5.82 of ANPS is essentially concerned with evaluating the risk that the project will present to the achievement of carbon reduction targets. In assessing that risk, the SST could (e.g.) take account of policies to be brought forward in the long term through the JZS. That was an issue distinct to the assessment of the effects in EIA terms, in respect of which the SST placed moderate weight against the proposed development in the planning balance. That approach was lawful.

The judge gave permission on this ground, but refused the ground on the merits.

International inbound flights

Following R (Finch) v Surrey CC [2024] PTSR 998 (Finch), GAL accepted and provided an assessment of the emissions of international inbound flights (in addition to international outbound flights). It had not previously assessed these due to the internationally recognised approach of excluding such flights to avoid double-counting, and them not being within JZS and the carbon budgets. The SST accepted this, and concluded that there was no meaningful benchmark against which to assess the GHG emissions of international inbound flights. The SST rejected contextualising against ICAO sector-based targets. Instead, she took a qualitative assessment based on the quantified emissions and concluded that they did not “materially affect her overall conclusions on significance”.

CAGNE argued that this was an unlawful approach adopting a misreading of Finch. Finch did not accept that the absence of a meaningful benchmark meant there could be no assessment of significance at all. In any event, given the significance of outbound international flights, it was illogical in the qualitative assessment to conclude that doubling to include inbound flights would not materially affect her overall conclusions.

The judge rejected this interpretation of Finch. Lord Leggatt in that case accepted that circumstances may arise where the considering whether an effect is significant may itself not be capable of meaningful assessment (or only be so capable to a limited or qualified extent). Here, there was not appropriate benchmark for significance. Further, the SST considered this issue to the limited extent she could (a qualitative basis) and concluded no effect on her conclusion to a material degree.

The judge concluded by noting he agreed with the similar analysis in R (LADACAN) v SST [2025] EWHC 3206 (Admin) (LADACAN). He refused permission.

Non-CO2 emissions

Also in its climate change assessment, GAL concluded that there was no meaningful way to assess non-CO2 effects, and also concluded that there was no meaningful benchmark upon which to rely. In so concluding, reliance was placed on R (BAAN) v SSLUHC [2023] PTSR 853 (BAAN) which determined (among other things) there was far from a scientific consensus on a “multipler” approach to non-CO2 emissions. As a result, SST accepted a qualitative assessment would be appropriate.

CAGNE argued that this approach was unlawful because, by the time the matter was before SST, it was clear on the evidence that a quantitative assessment of the impacts on non-CO2 effects was possible and should be done. Given that evidence, a proper and precautionary approach would be to conduct a quantitative assessment.

The judge rejected this argument. He first noted that CAGNE accepted a qualitative approach at the time of the examination. So, it accepted that a qualitative approach is lawful in principle. The question, then, was the evidence before the SST. The ExA had accepted CAGNE’s position that an absence of settled methodology did not prevent using a valid methodology, but that methodology must still produce plausible outcomes. The Examining Authority concluded, and the SST agreed, with a qualitative assessment which recognised that non-CO₂ effects would add to the magnitude of impacts and have a net warming effect. There is no doubt the SST considered CAGNE’s arguments on this point. Thus, it was a matter for the SST to decide this issue and, per Finch, it is a matter of judgment. Ultimately, the SST was not persuaded by CAGNE’s arguments; indeed, no scientific or policy consensus on a meaningful and reliable qualitative assessment of impact was provided. CAGNE did not suggest agreement had been reached on these issues, or that a scientific consensus had been reached on a method in relation to a planning decision. As to the precautionary principle, the judge concluded this went nowhere as the SST had assessed on a qualitative basis. Finally, this was a point managed looking forwards in the JZS anyway.

The judge accepted the analysis in LADACAN. The judge noted that, essentially, this ground reflected frustration on CAGNE’s part that the SST is unwilling to accept that the methodological problems and uncertainties have been overcome. However, the SST was not persuaded and her conclusions were lawful. Permission was refused.

Failure to comply with the EIA Regulations

Under this heading Mr Barclay argued that the SST had muddled her assessment of effects by focusing on carbon budgets and not making clear and reasoned findings on the proposed development’s significant environmental effects. The judge rejected this as the SST had so considered and concluded there would be significant environmental effects. Reliance on recognised guidance to explain this effect is lawful. It is also legitimate for the SST’s conclusions to be framed within the relevant statutory and policy framework.

The judge rejected an argument by Mr Barclay that mitigation measures are insufficient by noting this is a matter for the SST to determine in her judgment. He also rejected an argument that the cumulative effects assessment failed to assess the third runway at Heathrow. The judge found no error in the SST’s conclusion that the potential Heathrow development was too early in the planning stage, and in any event given the national effects of emissions there is no reason to pick one development over another. In any event, this was addressed through comparison against carbon budgets.

The judge refused permission.

CAGNE Ground 4 – JZS delivery risk

As part of its environmental assessment, GAL relied upon the JZS high ambition scenario. While Interested Parties had raised concerns about JZS, the SST noted and accepted the conclusions of the ExA that the policy was robust and review mechanisms were included as necessary. CAGNE argued that this was unlawful as she had failed to take into account the “Policy Commission Returns” that the DfT had in its hands as part of the process of the DESNZ complying with ss.13 and 14 CCA 2008 (which CAGNE argued showed increased delivery risk compared to the published JZS). It also argued that modelling for JZS: One Year On should have changed the approach adopted by SST. In short, CAGNE argued that GAL using the JZS high ambition scenario for its quantitative GHG emissions assessment meant the SST was obliged to consider whether that scenario was a reliable basis for that assessment.

The judge began by noting that the principal CCA 2008 duties and obligations apply to the SSESNZ and they are not required to be undertaken in a “multipartite” manner by many secretaries of state. The JZS is merely a “component of the panoply of proposals and policies” in place to meet the objectives of the CCA 2008. Following R (Global Feedback) v HM Treasury [2024] 1 WLR 2923, it is for SSESNZ to operate the legislative machinery. Thus, the judge concluded it was not for SST to conduct an ad hoc review of delivery risk as part of a decision on consent for a development. The judge concluded it was not arguably irrational for the SST to decide not to reduce the weight placed on the JZS high ambition scenario, or to consider the policy in the context of the CCA and the statutory requirements therein. Ultimately, CAGNE’s challenge was to an individual decision not the efficacy of the overall statutory and policy arrangements.

Permission was refused

CAGNE Ground 6, Barclay Ground 5 – noise issues

CAGNE argued that the SST had, first, erred in giving neutral weight to noise effects which were identified as “significant” in the EIA assessment. The judge rejected this. That weight is a matter for the decision-maker is a cardinal principle of planning. The SST’s assessment of weight was done with the residual effects (including significant effects) in mind. Indeed, here, while there were significant effects, they were not above the Significant Observed Adverse Effect Level. In any event, the judge recognised that neutral weight is not the same as no weight. The former is apposite where factors point in both directions and overall balance to neutral weight. Ultimately, the conclusions of the SST were rational within the policy framework. While permission was given the ground was rejected on the merits.

Mr Barclay argued that the SST had failed to ensure that benefits are shared between the aviation industry and local communities” of “future growth in aviation” (wording used in the Aviation Policy Framework). In addition, the SST had applied an unlawful temporal gloss on the approach to sharing benefits (which was that benefits be shared “as soon as reasonably practical”). The judge rejected these arguments. The SST did consider the sharing of benefits; the APF identifies two practical measures through which this can be secured (reducing and mitigating noise as airport capacity grows, and sharing technology improvements as noise levels fall). The SST’s conclusions reflected these measures, and they were secured by requirements in the Order. As to the timing of such sharing, the APF does not stipulate a timing requirement. In any event, “as soon as reasonably practicable” reflects a practical understanding and application of the policy to the real world. That is necessarily the case where some benefits will come from technology improvements over time.

The judge refused permission on this ground.

CAGNE Ground 7 – wastewater treatment

By this ground CAGNE challenged the technical wording of requirement 31 of the Order. In particular, it argued that the use of any wastewater treatment works (WWTW) built was not secured by the Order, and that the requirement had an impermissible tailpiece which allowed GAL and Thames Water to agree an outcome outside of the scope of what was contemplated by the Order.

The judge rejected both of these arguments. In respect of bringing the WWTW into operation, the SST was not irrational to conclude the terms of the Order were sufficient. This issue was considered by the SST, and it was rational for the SST to conclude that any risk identified that the WWTW would not come into use did not require further wording in the Order. The judge noted it was fanciful to contemplate GAL would build the WWTW but then not use it (as was CAGNE’s argument). As to the tailpiece, the judge did not accept that it provided flexibility to allow a development of a very difference scale and impact from that applied for. He granted permission on the ground but refused it.

Comment

This case is an important one, concerning one of the largest infrastructure projects currently consented in the UK, and providing for the elusive second operational runway at an airport. It shows that the High Court will take seriously the expedition intended by the changes brought forwards in consequence of Lord Banner’s review, and will make decisions (such as on disclosure) to facilitate that expedition.

As to the merits of the case, the grounds raise important national issues related to airport policy and GHG emissions. On the former, it will be important to keep in mind the ongoing review of the ANPS and the progress being made at Heathrow. On the latter, the case represents a chance (lost in the LADACAN case because a time extension for permission to appeal was refused: [2026] EWCA Civ 648) for claimants to challenge the existing case law on the assessment of non-CO₂ and inbound flight emissions. At the time of writing, Mr Barclay had already applied for permission to appeal to the Court of Appeal from the judge on his Grounds 1 and 4; that application was rejected on the papers. The seven-day period for any application for permission to appeal ends on 30 June 2026; it may well be that this is not the last word on Gatwick’s second runway.