Factual and Procedural Background
The appeal concerned the decision of the Department for Infrastructure (“DfI”) to proceed with the first phase of the A5 Western Transport Corridor dual carriageway scheme. The High Court quashed that decision on environmental impact assessment, climate-change and human-rights grounds. [1][2][3][4][5]
The scheme concerns an approximately 52.8-mile road linking two locations in Northern Ireland and has been supported on network and road-safety grounds. The litigation followed earlier decisions concerning the scheme being quashed in 2013 and 2018. [6][7][8]
Following an updated environmental statement, consultation and a Planning Appeals Commission inquiry, the Executive approved the scheme on 2 October 2024. Judicial review proceedings followed. [9][10]
The Court of Appeal considered an appeal by DfI and a climate-related intervention by the Department of Agriculture, Environment and Rural Affairs (“DAERA”). The climate issue had been remitted to the High Court for consideration of further evidence before the appeal resumed. [11][12]
Legal Issues Presented
- Whether the decision complied with the environmental impact assessment obligations under the EIA Directive and the Roads (Northern Ireland) Order 1993. [13][14]
- Whether the High Court was correct to quash the decision on human-rights grounds. [13][15]
- What section 52(1) of the Climate Change Act (Northern Ireland) 2022 required of DfI, and whether the decision was irrational because of an evidential gap. [16][17]
- Whether the High Court had dealt correctly with the climate-change evidence following remittal. [18][19]
- Whether, even if illegality were established, the decision should nevertheless be quashed. [19]
Arguments of the Parties
Appellant and Departmental Arguments
- The EIA process did not require every item of environmental information to be included in the original environmental statement. The additional information concerning induced cross-border travel was assessed before authorisation and did not require further consultation. [20][21][22]
- The methodology for estimating induced demand followed recognised technical guidance, and the additional greenhouse-gas emissions remained within the previously assessed “large adverse” category. [23][24][25]
- Human-rights obligations had been addressed through several Human Rights Act Impact Assessments, consultation and a balancing of private interference against the public benefits of the scheme. [26][27][28]
- The refusal to impose a time-limit on the authorisation was justified by funding uncertainty, possible legal delays, competing spending priorities and contractor negotiations. [29][30][31][32]
- Section 52 required DfI to act, so far as possible, consistently with statutory emissions targets, but did not require project-specific emissions to be included in a completed Climate Action Plan before authorisation. [33][34][35]
- The extensive technical evidence demonstrated that the scheme would not prevent achievement of the statutory climate targets and that the High Court had wrongly rejected or misunderstood that evidence. [36][37][38]
Respondents’ Arguments
- The EIA was deficient because it did not expressly assess greenhouse-gas emissions from induced cross-border journeys, and later estimates had not been disclosed for public consultation. [39][40]
- The decision failed to address adequately the interference with affected persons’ rights under Article 8 of the ECHR and Article 1 of Protocol 1, particularly when rejecting the recommendation that authorisation be time-limited. [41][42][43][44]
- The department had a duty to give adequate reasons for rejecting the Planning Appeals Commission’s recommendation. [42][45]
- The climate decision was unlawful because there was insufficient evidence showing how the scheme fitted within the statutory emissions targets and because no completed Climate Action Plan provided the necessary pathway. [46][47]
Table of Precedents Cited
| Precedent | Rule or Principle Cited For | Application by the Court |
|---|
| Buick [2018] NIQB 43; [2018] NICA 26 | Limits on departmental decision-making while the Executive was suspended. | Cited as the basis on which an earlier decision concerning the road was quashed. [8] |
| R (Blewett) v Derbyshire CC [2004] Env LR 29 | An environmental statement is not required to meet a “counsel of perfection” standard. | Relied upon in the appellant’s argument concerning the adequacy of the environmental statement. [21] |
| R (Friends of the Earth Ltd and another) v Secretary of State for Transport [2021] PTSR 190 | Principles governing the adequacy of an environmental statement. | Considered in the appellant’s submissions on EIA adequacy. [21][48] |
| R (Davies) v Secretary of State [2008] EWHC 2223 (Admin) | Further environmental information may arise during an inquiry and need not all be contained in the original environmental statement. | Supported the appellant’s contention that later information could lawfully be considered before authorisation. [48][49] |
| Re Moreland and Owenvarragh Residents Association [2022] NIQB 40 | Adequacy of an environmental statement. | Cited among the authorities relied on by the appellant. [49] |
| Re Newry Chamber of Commerce [2015] NIQB 65 | Adequacy of an environmental statement. | Cited in the appellant’s submissions on EIA compliance. [49] |
| R (Friends of the Earth Ltd) v Secretary of State for International Trade/Export Credits Guarantee Department (UK Export Finance) [2022] EWHC 568 (Admin) | The importance of assessing emissions against climate objectives. | Illustrated the more purposive approach that may be required in climate-related EIA challenges. [50] |
| Finch v Surrey County Council [2024] UKSC 20 | A purposive interpretation of EIA obligations. | Distinguished because the present case involved substantial consultation on greenhouse-gas effects rather than a conscious exclusion of indirect emissions. [51][52] |
| R (on the application of Champion) v North Norfolk District Council and another [2015] UKSC 52 | Public consultation as an integral feature of EIA. | Supported the court’s description of the consultation obligations under the EIA Directive. [53] |
| Berkeley v Secretary of State for Environment [2001] 2 AC 603 | The public must have an opportunity to participate in the prescribed environmental decision-making process. | Used to emphasise the democratic and inclusive purpose of EIA consultation. [53][54] |
| Secretary of State for Communities and Local Government v Allen [2016] EWCA Civ 767 | A decision-maker rejecting an inspector’s view must explain the rejection fully and clearly. | The court held that the Departmental Statement adequately explained the rejection of the time-limit recommendation. [45][55] |
| South Bucks District Council and another v Porter [2004] UKHL 33 | Reasons must be intelligible, adequate and address the principal important controversial issues. | Considered in the respondents’ reasons challenge. [56] |
| R (Nash) v Chelsea College of Art & Design [2001] EWHC Admin 538 | The greater the interference with human rights, the more justification may be required. | Cited in the respondents’ argument concerning the adequacy of the human-rights reasoning. [57] |
| R (on the application of the Spitalfields Historic Building Trust) v London Borough of Tower Hamlets and another [2025] UKSC 11 | The level of justification required for substantial human-rights interference. | Cited alongside Nash in the reasons challenge. [57] |
| R(O) v Home Secretary (SC (E)) [2023] AC 255 | Statutory interpretation according to ordinary meaning, legislative purpose and statutory context. | Applied when interpreting section 52 of the 2022 Act. [58] |
| R (PACCAR Inc and others) v Competition Appeal Tribunal and others [2023] 1 WLR 2594 | Principles of statutory interpretation. | Applied with other Supreme Court authorities to section 52. [58] |
| For Women Scotland v Scottish Ministers [2025] UKSC 16 | Principles of statutory interpretation. | Applied in determining the ordinary meaning and purpose of section 52. [58] |
| Coolglass Windfarm v An Coimisiún Pleanála [2026] IESC 5 | The meaning of acting “in a manner consistent with” climate objectives. | The court adopted its analysis while holding that section 52 imposed a flexible but more exacting obligation. [59][60][61][62] |
| R (Plantagenet Alliance) v Secretary of State for Justice [2015] 3 All ER 261 | The public authority’s duty to make sufficient inquiry before exercising its powers. | Used to explain the application of the Tameside duty under section 52. [63] |
| Re McAleenon’s Application [2024] 3 WLR 803 | The public authority determines relevant facts subject to supervisory rationality review. | Supported the court’s limited role in reviewing the technical evidence. [63][64] |
| Packham v SOS Transport [2021] Env LR 10 | The interaction between infrastructure decisions and statutory climate obligations. | Provided a parallel for applying Tameside principles to climate-related infrastructure decisions. [65] |
| R (Friends of the Earth) v Heathrow Airport Limited [2020] UKSC 52 | Application of Tameside principles to climate obligations in planning decisions. | Supported the conclusion that project authorisation did not require a precise project-level climate pathway. [65] |
| R (Mott) v Environment Agency [2016] 1 WLR 4338 | Courts must avoid substituting their view for that of a conscientious decision-maker, particularly regarding technical predictions. | Applied in rejecting the High Court’s treatment of uncontradicted specialist evidence. [66][37] |
Court's Reasoning and Analysis
Environmental Impact Assessment
The court held that the environmental statement was not deficient overall. The traffic and demand modelling had been prepared in accordance with technical guidance, and the Planning Appeals Commission considered it adequate. [67][68]
The additional assessment of induced cross-border journeys supplied further statistics required by the Planning Appeals Commission. The relevant greenhouse-gas effects had already been considered and remained within the “large adverse” category. [69][70]
Because greenhouse-gas emissions had been the subject of substantial consultation, the case was materially different from Finch. Requiring a further environmental statement or additional consultation imposed an excessively demanding standard. [52][71]
The court allowed the appeal on the EIA ground and reversed the High Court’s decision. [72][73]
Human Rights
The court accepted that the scheme substantially affected private and property rights, but found that those rights had been considered through the Planning Appeals Commission process, departmental assessments and public consultation. [74][55]
The Departmental Statement gave discernible reasons for rejecting a rigid time-limit, including the scale of the project, public-expenditure constraints, possible legal delays and commercial negotiations. The decision-maker was entitled to conclude that such a limit was unrealistic. [55][32]
The court also considered that quashing the vesting orders could prolong, rather than reduce, the uncertainty affecting landowners. It found no substantial prejudice and no inadequate reasons. [75][76]
The court allowed the appeal on the human-rights ground and reversed the High Court’s findings. [77]
Climate Change Act 2022
Section 52 imposed a mandatory duty on each Northern Ireland department to exercise its functions, so far as possible, consistently with the statutory emissions targets. The duty was more exacting than a mere obligation to have regard to climate objectives, but it did not prohibit authorising a road project that increased emissions. [58][61][62][78]
Compliance required a rational conclusion, based on adequate inquiry, that the decision was consistent so far as possible with the statutory targets. It did not require project-level emissions to be specified in a completed Climate Action Plan or placed on a precise quantified pathway before authorisation. [79][34][63]
The court found that DfI possessed sufficient information about scheme emissions and transport-sector policy pathways. The further technical evidence from DAERA and specialist witnesses filled the alleged evidential gap and was broadly consistent with the material supporting the original decision. [80][36][81]
The High Court had wrongly conducted an overly merits-based assessment of uncontradicted technical evidence and had misunderstood the relationship between the project, Northern Ireland-wide targets and the Climate Action Plan. [66][82][83]
The court held that DfI complied with section 52 and that the irrationality and failure-of-inquiry findings could not stand. [84][85][86]
Holding and Implications
APPEAL ALLOWED. The Court of Appeal set aside the High Court’s order and dismissed the judicial review application on all grounds. Costs were to be addressed separately. [87]
The direct effect was that the decision to proceed with the A5 Western Transport Corridor scheme was restored. The judgment clarified that section 52 requires a department to undertake adequate inquiry and make a rational assessment of consistency with statutory climate targets, but does not require a completed Climate Action Plan or a precise project-specific emissions pathway before every infrastructure decision. [78][79][63][87]