R (WWU) v CMA decision

On 22 January 2026, the Administrative Court issued a significant judgment in terms of economic regulation, considering for the first time the standard of review that the UK Competition and Markets Authority (the CMA) should adopt in determining energy price control appeals. 

This decision provides welcome clarity in respect of the appeal regime, which operates as an important safeguard for energy network companies subject to price control regulation (and is also a feature of other regulated sectors).

Case timeline

The case has an interesting and lengthy procedural history:

• In December 2020, Ofgem issued its “RIIO-2” price control decision for electricity transmission, gas transmission and gas distribution companies in GB. 

• In March 2021, all nine affected companies appealed this price control decision to the CMA. The CMA issued its final determination in November 2021, finding in favour of the appellants on some grounds of appeal, but not on other issues.

• Wales & West Utilities Limited (WWU), one of the appellants, filed an application for judicial review of the CMA's final determination on 28 January 2022. 

• Permission was initially refused on the papers by Henshaw J on 30 June 2022, and again at an oral renewal hearing by Mostyn J on 21 November 2022.

• On renewal, permission was granted by the Court of Appeal in March 2023. However, a substantive hearing of WWU’s application did not take place until October 2025 (a delay of two and half years), with judgment finally handed down on 22 January 2026. 

As a result of this protracted timeline, WWU’s application for judicial review was not determined before Ofgem issued its final determinations to GB electricity transmission, gas transmission and gas distribution companies in respect of the subsequent “RIIO-3” price control in December 2025.

Summary of findings

WWU’s application was dismissed, with the Administrative Court deciding that, although the CMA had made certain errors, these did not affect the substantive outcome. Key points are as follows:

1. The judgment confirms that the appeal regime is not a fresh hearing of all the matters before Ofgem, but rather requires the CMA to determine if Ofgem’s decision is 'wrong' based on one of the prescribed statutory grounds under the relevant energy legislation.

2. It reinforces that appeals must directly challenge the regulator’s specific reasoning and evidence, and appellants cannot present entirely new arguments on appeal.

3. The judgment appears to lower the bar for demonstrating that Ofgem has erred by failing to 'have regard' or 'give the appropriate weight' to its statutory duties. Specifically, the Court found that appellants need to show an alternative approach is 'materially' better rather than 'clearly superior' (as previously stated by the CMA). While it is difficult to quantify the difference between these tests, this does seem to put appellants on a better footing and decrease the degree of deference shown to Ofgem. 

4. The Court found that the CMA had erred in interpreting the “financing duty” in the legislation, which requires Ofgem to have regard to the need to secure that regulated companies are able to finance their activities. The legislation requires Ofgem to consider the financing needs of each individual company rather than companies on a collective basis. The Court emphasised that this does not equate to a duty to ensure that each licence holder can finance its activities – rather, it is a duty to “have regard to the need” to secure.

5. The Court upheld the CMA's broad case management discretion. This includes the CMA's power to decline further inquiry into arguments that an appellant has not supported with evidence.

6. Finally, the judgment demonstrates the degree of deference the Court will afford to specialist regulators on judicial review. It shows that the Court is likely to defer to the CMA's decisions, provided its reasoning is logical, coherent, and addresses the specific arguments and evidence presented. 

Given similarities between the energy price control appeal regime and the appeal regimes applying in other regulated sectors (such as airports), it seems likely that this judgment will have wider read-across.

Norton Rose Fulbright represented National Grid Electricity Transmission plc (NGET), an interested party to the judicial review proceedings.