Planning judicial review: further changes afoot

On 30 April, we provided an update on proposals relating to judicial review in Building Our Nuclear Nation, in light of the recent changes introduced by the Planning & Infrastructure Act 2025, and the decision by Mrs Justice Lieven to refuse permission to apply for judicial review of the DCO for the Stonestreet Green Solar project. There is now more to update you on relating to judicial review and statutory challenges in the planning and infrastructure context and my colleague Craig Shearer has highlighted the key takeaways below.

Case law update

Firstly, two recent judgments handed down by the Courts, Arun District Council v Secretary of State for Housing, Communities and Local Government and others [2026] EWHC 1172 and R (Luton and District Association for the Control of Aircraft Noise) v Secretary of Transport [2026] EWCA Civ 648, demonstrate how procedural deadlines are currently being enforced.

Arun District Council: strict service requirements under section 288 of the Town and Country Planning Act 1990 (“1990 Act”).

In Arun District Council, the High Court dismissed a statutory review challenge, under section 288 of the 1990 Act, because the claimant failed to serve the claim form on all required “persons aggrieved” within the statutory six‑week period. Complications arose when the claimant attempted to serve the developer by sending the documents to the planning consultant on the day of the 6 week deadline, 3 October 2025. The consultant later clarified they were not authorised to accept service and had not forwarded the documents to the developer. It was not until 4 November 2025, thirty-two days after the deadline, that the claimant served the developer directly and sought an extension of time from the Court.

From this set of facts, a particularly novel question arose: could the claim proceed against the Secretary of State alone, given they had been properly served and had actively participated in the proceedings, despite the developer not being served properly but expressing no interest in taking an active role? The Court firmly held that it could not. The failure to serve the developer within the prescribed timeframe constituted a breach of Practice Direction (PD) 54D paragraph 4.11, which undermined the entire claim. The Court reaffirmed that a section 288 challenge represents a single statutory claim rather than distinct claims against separate defendants. As a result, the lack of timely service deprived the court of jurisdiction to hear the claim. Interestingly, the absence of prejudice to the developer and the decision not to participate did not influence the outcome. Consequently, the Court refused permission for the claim to proceed.

The judgment underscores the unforgiving nature of existing statutory deadlines: even simple procedural errors can be fatal, regardless of whether the unserved party wishes to participate. 

Luton Airport: refusal to extend time for an appeal

In the Luton and District Association for the Control of Aircraft Noise (LDACN) case, the Court of Appeal refused an application for the extension of time for permission to appeal against the dismissal of a judicial review challenge of a DCO to expand Luton Airport.

Practice Direction (PD) 52D paragraph 17.3 imposes a seven-day time limit for filing an appellant's notice in NSIP challenges, with a target of four weeks for determination of permission applications and four months for substantive appeals. The time to appeal expired on 15 December 2025. LDACN did not file its appellant's notice until 24 December 2025 and did not apply for an extension of time until 22 January 2026. The delay meant the target date for the determination of the permission application (12 January 2026) could not be met, nor could the target date for substantive hearing (15 April 2026). 

The court considered the case of Denton v TH White Ltd [2014] EWCA Civ 906 which set out the three stage test for extensions of time:

• Seriousness and significance of the breach (stage one);
• The reason for the default (stage two); and
• Evaluation of all the circumstances (stage three).

It was acknowledged that LDACN could not satisfy the first two stages. When examining the third stage, the Court emphasised that adherence to procedural rules and practice directions is especially crucial in NSIP challenges. As DCOs tended to raise public interest points, the fact that the challenge touched on such matters did not warrant an extension.

This decision illustrates the Courts’ increasing reluctance to permit late challenges in the NSIP context. This in turn reinforces the Government’s view that further reform is needed to prevent delays caused by procedural slippage.

Further Reforms 

Judicial review reform was recently discussed by the Civil Procedure Rule (CPR) Committee at their annual open meeting on 8 May 2026. The minutes indicate that the Committee discussed procedural changes to provide greater clarity and speed to the NSIP judicial review process by introducing shorter timescales in the High Court for judicial review of DCOs and NPSs and updating guidance to clarify that NSIP appeals in the Court of Appeal are considered by judges with relevant experience. It was resolved by the Committee that the amendments to the CPR to reduce the timeframe for serving pre-permission documents (from 7 to 3 days) and for filing and serving the detailed grounds of defence (from 35 to 28 days) would be included in the upcoming CPR amendment cycle, as part of the October 2026 common-commencement date. Further consideration would be given to updating the guidance relating to the Court of Appeal judges.

In addition, HM Treasury’s policy paper Getting Britain Building: Reforming Judicial Review for Infrastructure was published on 20 May 2026 and proposes two reforms to the current process in consenting major infrastructure. 

• The first proposed reform plans to introduce a fixed challenge window, creating a defined period in which legal challenges can be brought. The challenge window would ‘open’ before a DCO is finalised, ensuring any judicial review grounds are raised early. The Secretary of State could then consider and address those issues before issuing the final decision. After that point, the Courts would be more likely to refuse challenges on the same grounds, or on issues not raised during the process, reducing late-stage judicial reviews. After this window closes, developers would have certainty that no new claims can be raised lat a later stage, preventing further delays.
• The second proposed reform looks to introduce a parliamentary authorisation mechanism. The proposal would allow certain energy projects to be designated as of “Critical National Importance”, with that designation approved by the House of Commons. The DCO process would still run as normal, but the final decision would also be put to a Commons vote. If approved, the resulting DCO would have a status similar to an Act of Parliament, meaning it could only be challenged on limited human rights grounds. This is intended to give stronger protection against legal delay for nationally significant energy projects. There is no mention of other key projects relating to the transport and water sectors.

These reforms signal a clear shift toward greater procedural discipline and stronger protection for nationally significant infrastructure. A fixed challenge window aims to force all legal issues to the surface early, reducing the scope for late or repeat claims, while the proposed parliamentary authorisation mechanism would give certain energy projects a level of legal finality comparable to primary legislation. Both measures are designed to address the delays and uncertainties highlighted in recent cases above, and to provide developers with a more predictable pathway through the consenting process.

The Government recognises that these reforms raise important legal, constitutional and practical questions. It has indicated therefore that the changes will not be introduced quickly, so it will be important to monitor their progress and how they evolve following further consideration.

If you have any queries relating to challenges to infrastructure projects, please contact Alex Minhinick.