The reform of the planning judicial review system

On 13 March 2026, we published an update on measures in the government’s publication Building Our Nuclear Nation, the response to the Nuclear Regulatory Taskforce’s recommendations, most likely to affect planning, environmental assessment and delivery. Today we want to highlight the proposals relating to judicial review, in light of the recent changes introduced by the Planning & Infrastructure Act 2025 (PIA) and the decision by Mrs Justice Lieven to refuse permission to apply for judicial review of the DCO for the Stonestreet Green Solar project.  

The government’s response highlights that judicial review plays a key role in holding public bodies to account but that repeated challenges can cause uncertainty, cost increases and delivery risks. The Taskforce estimated that the direct costs associated with judicial reviews for some significant highway projects ranged between £60 to 120 million and an assessment by DESNZ concluded that an adverse Supreme Court ruling could expose between £1.7 to 2 billion in costs for some projects. There are also indirect costs from supply chain disruptions, decommissioning shortfalls and higher financing costs, as well as significant delay which can hinder the delivery of an infrastructure project. The need for additional resilience and resourcing in the Courts was also highlighted.

What reforms have been recently introduced? 

Two provisions of the PIA which came into force on 18 February 2026 go some way to alleviate the concerns raised:

• Section 13 removes the right to appeal to the Court of Appeal in NSIP cases High Court judges deem to be totally without merit. It is worth noting that Mrs Justice Lieven has recently refused permission for Aldington and Bonnington Parish Council to apply for judicial review of the development consent order for the Stonestreet Green Solar project. This is the first example of section 13 being used (please see our earlier blog which highlights where it was not used), with the key points to note being:
  • The permission was considered at an oral permission hearing on 23 April 2026 and there was no paper stage. This follows new paragraph 3.7 in Practice Director 54D;
  • The challenge was brought on three grounds concerning heritage matters, consistency with an appeal decision for another solar farm, and the reasons given the Examining Authority and the Secretary of State for Energy Security and Net Zero. The judge held that the application was totally without merit, which engaged section 13.
• Where a planning permission is subject to legal challenge, section 56 extends the time for implementing a planning permission or listed building consent. If permission is granted for judicial review, the time frame for implementation will be extended by one year in the case of High Court proceedings, an additional year if the case goes to the Court of Appeal, and a further two years if the case goes to the Supreme Court. For outline planning permissions, these extension periods apply both to extend the period for reserved matters applications as well as the implementation period that is running when the proceedings are brought. The same protection applies for listed building consents. However, if an implementation period has already expired, it cannot be extended under section 56.

What reforms are proposed? 

The Nuclear Regulatory Taskforce consider that further changes to the regime are required, as detailed in recommendations 20 and 21 of its November 2025 report. The Government agrees that these measures should be introduced.

Recommendation 20 is made up of two parts. The first part involves amendments being made to the cost cap for judicial reviews and to Article 14 of the Aarhus Convention to endorse the principle of the measures:

• Where the court determines that there has been a “misuse of judicial review” and Counsel and solicitors certify that the grounds have a more likely than not chance of success, there should be an automatic removal of the costs protection;
• The cost cap is raised to take account of inflation since 2013 and linked to inflation going forward. Guidance should also be published to encourage the setting of higher caps or the use of direction where there is a misuse of the process or intention to cause delay;
• The cost cap should be cascaded so that it is doubled for each stage of a challenge;
• Where crowd funding is utilised, the cap should be set at 70% of total funds raised, which balances access to justice and the need to reduce delays;
• The costs cap for the decision-maker being challenged should always be set at a level which is at least 5 times the claimant’s cap in order to balance the relationship between a challenger and the decision-maker. 

Recommendation 20 also sets out that section 13 of the PIA should be extended beyond judicial review to NSIPs to challenges relating to nuclear site licensing and permitting decisions. If claimants lose on an issue relating to the DCO, they should not be able to re-run the same dispute at the site licensing or environmental permitting stages.

Recommendation 21 states that the Government should commit to indemnifying nuclear developers against any damages they incur as a result of proceeding with their project while a judicial review is being decided. This would require updates to be made to the Civil Procedure Rules (CPR). 

What is the timeline? 

The Government intends to publish a working paper in Summer 2026 on the detailed proposals to extend the section 13 changes to judicial reviews relating to environmental permitting and nuclear site licensing and consider the benefit of extension to other planning regimes. The Government’s intention is to introduce relevant legislation following consultation and invite the CPR Committee to make consequential changes to the CPR and the Environmental Costs Protection Regime by the end of 2027. The Government will also publish proposals in Summer 2026 to offer targeted indemnification for nuclear projects where the planning consent is subject to judicial review, where this would materially support delivery and represent value for money. 

If you have any queries on judicial review challenges, please contact Alex or me.