The firm’s report, ‘Realising the benefits of competitive markets’, calls for opt-out cases in the Competition Appeal Tribunal (CAT) to be extended to cover data privacy breaches, consumer protection violations and other mass harms as well as competition law breaches. It recommends introducing pre-action protocols and improving early case management, including costs budgeting and stricter timetabling to keep budgets under control in complex cases, and reversing the effects of the Supreme Court’s PACCAR decision to encourage funders to invest.
It recommends the CAT bring approval of funding arrangements forward to the certification stage—helping parties avoid later disputes.
If boosted to work more effectively, the CAT could deter between £12.1bn and £24.2bn of rip-off prices and other harms to consumers and small businesses annually, it finds, equivalent to up to £840 per household.
However, the report, which uses data from litigation analytics platform Solomonic, notes the number of cases has declined from 17 in 2023 to only three filed in the first nine months of 2025. It highlights years of delays in cases, which it attributes to procedural complexities, strategic litigation by defendants, and the PACCAR Supreme Court decision which has stalled litigation funding.
Genevieve Quierin, partner at Stephenson Harwood, said: ‘The regime stands at a critical juncture, facing challenges that undermine its ability to operate effectively.
‘Rather than restrict, we need to nurture the system.’
In his foreword to the report, former CAT president Sir Gerald Barling says that he hopes the government, which is currently considering a review of the regime, will not curtail or remove the ‘only means by which multiple claimants—each suffering relatively small amounts of financial loss—can achieve justice’.
