Arnold Ayoo represented the Competition and Markets Authority (“CMA”) in its successful defence of a judicial review application, brought by a gas and distribution network, in relation to the CMA’s determination of a price control appeal.

The judgment of Mr Justice Sheldon, handed down on 22 January 2026, is a significant High Court examination of a regulatory decision on energy pricing.

The Gas and Electricity Markets Authority (“GEMA”) (the governing body of Ofgem) makes price control decisions, which concern the prices gas distribution networks (GDNs) are permitted to charge to energy suppliers. Such decisions directly affect how much consumers pay for their energy. This case related to a price control decision covering the period from 1 April 2021 to 31 March 2026 (“RIIO2”)

Affected gas distribution networks can appeal such price control decisions to the CMA. Thereafter, a GDN can pursue a judicial review of the CMA’s decision.

Wales & West Utilities Limited (“WWU”), which owns and operates the regional gas distribution network in Wales and the South West of England, appealed to the CMA in respect of GEMA’s RIIO2 decision, and subsequently sought a judicial review of the CMA’s decision.

In a 93 page judgment, Mr Justice Sheldon dismissed all grounds of WWU’s challenge. The judgment provides guidance as to the standard of review to be applied by the CMA on such appeals and addresses the proper interpretation of the Financing Duty in section 4AA(2)(b) of the Gas Act 1986.

Arnold Ayoo was instructed by Daniel Barnett and the CMA legal team, led by Ben Lask KC from Monckton Chambers and Christopher Brown from Matrix Chambers.

Read the judgment in full: WWU v CMA [2026] EWHC 99 (Admin)