There is a widely-held perception that judicial review cases have risen significantly in the last decade, leading to political concern about the hampering of growth and investment. This has been the prompt for legislative change. 

We have undertaken extensive research to analyse the key regulatory judicial reviews in England and Wales over the last 20 years and see whether these concerns reflect the facts. Our ten key takeaways from this research are summarised below: 

1. The increase in applications for judicial review in the regulated sectors is significant. In 2017, the number of applications for judicial review of decisions in the regulated sectors doubled from 2016. This increase was sustained until 2022 when the number of applications doubled again.
2. The energy and water sectors have dominated applications for judicial review over the last 10 years. In particular, over 60% of cases have been brought in the energy sector. This reflects the rise of climate change related litigation, often by campaign groups who benefit from delay and face more limited risk due to the application of costs caps designed to facilitate access to environmental justice.
3. There has also been an increase in applications under the Freedom of Information Act 2000 and the Environmental Information Regulations 2004, with the number of requests in 2024 the largest number since monitoring began. These can often provide important information on which to base a claim.
4. Ofgem is most challenged regulator, closely followed by Ofwat.
5. DEFRA is the most challenged government department, with cases relating to river basin management plans, environmental permitting, agricultural pollution, and climate adaptation strategies. DESNZ and the Department for Transport also frequently appear as defendant government departments.
6. The most commonly pleaded judicial review ground is illegality. It features in over 70% of the cases we have tracked. It is also the most successful judicial review ground, reflecting the fact that illegality is ‘hard-edged’ rather than involving a broad margin of discretion.
7. Irrationality is also regularly pleaded – in over 55% of the cases we have tracked – but has a much lower success rate given the deference the Administrative Court tends to show authorities as experts in their field.
8. Over 75% of the cases we have tracked plead both illegality and irrationality to strengthen their chance of success. Procedural impropriety, legitimate expectation and human rights are also pleaded commonly.
9. The average time between the grant of permission and substantive hearing is 12 months.
10. To manage its rising caseload, the Administrative Court has affirmed and made full use of its existing powers. This includes underlining strict adherence to the time limit for making an application for judicial review in the recent case of R (Hynot) v Secretary of State for Energy Security and Net Zero [2025] EWHC 2644 (Admin), particularly for claims challenging Nationally Significant Infrastructure Projects (NSIPs). 

The evidence suggests that applications for judicial review in the regulated sectors will continue to increase in 2026.

In the event that section 13 of the Planning and Infrastructure Act 2025 demonstrably reduces delay for NSIPs, this may – as highlighted in our previous Regulatory Trends article – lead to calls for the relevant changes to be rolled out more widely. 

We will continue to track and monitor developments.