Effective collective actions could deliver £24 billion annual boost to UK economy, report finds

The United Kingdom could reap an annual economic benefit of up to £24.2 billion if its collective action regime were strengthened to deter anti-competitive behavior, according to a new report by Stephenson Harwood and litigation analytics firm Solomonic. The study warns that filings at the Competition Appeal Tribunal (CAT) have “collapsed” to just three in 2025, down from a high of 17 in 2023, as the system faces growing procedural and funding challenges.

The report attributes the decline to delays, strategic litigation by defendants, and the lingering effects of the Supreme Court’s PACCAR ruling, which cast uncertainty over the enforceability of many litigation funding agreements. Yet the analysis—supported by a detailed economic model—suggests that a more effective CAT could deter between £12.1 billion and £24.2 billion in consumer and small-business harm annually, equivalent to a benefit of £840 per household through fairer prices and increased competition.

“The £24 billion figure is the upper bound of estimated annual economic impact,” said Adam Polonsky, one of the report’s contributors. “It quantifies the potential ‘competition dividend’ from deterring anti-competitive conduct through an effective collective actions regime. We used conservative assumptions, looking only at sectors with demonstrated CAT activity and attributing a modest share to collective actions within the broader enforcement ecosystem.”

The report arrives as the UK government considers a formal review of the opt-out regime, which was introduced in 2015 to enable consumers and businesses to pursue redress collectively. In a foreword, former CAT president Sir Gerald Barling warned that curtailing collective actions “would be a significantly regressive step” and would “reduce the valuable deterrent effect of compensation claims.”

Stephenson Harwood partner Genevieve Quierin, who co-authored the report, said the regime stands “at a critical juncture.” She urged reforms to “expand the regime beyond competition-only claims, strengthen case management, improve consumer engagement, and reverse the uncertainty permeating the system.”

Polonsky agreed that PACCAR has created a chilling effect. “One of the primary causes [of the decline] is uncertainty following PACCAR and questions about whether the large sums invested in CAT claims will be recoverable with a sufficient return to justify the risk,” he said. “We advocate urgent action by the government in line with the Civil Justice Council’s conclusions. Access to litigation funding at sensible levels of return will be instrumental in instilling consumer confidence and putting the regime on a sound footing.”

The report recommends legislative reform to reverse PACCAR, as well as expanding the CAT’s remit to include data privacy, consumer protection, and other mass harms. Polonsky said such an evolution would be “a sensible development,” noting that “there is no logical reason why the regime cannot operate to service the needs of all mass torts.”

Improved case management was another focus. “I would like to see the CAT employ much firmer case management from an early stage,” Polonsky said. “Courts need to be aware of defendant tactics, which can draw out proceedings and put pressure on funded budgets.” He added that better costs management and “exploring the deterrent effect of making recoverable certain funding costs” could improve efficiency.

The report also highlights the need for earlier class identification and communication, a recommendation Polonsky supports. “It reinforces a distribution plan and is likely to ensure better take-up rates,” he said, suggesting that class engagement should begin as early as the certification stage and even use “defendant platforms to raise awareness in neutral terms.”

Polonsky also called for investment in CAT resources, including more judges and support staff. “More court space and increasing the size of the excellent administrative and support teams would be a significant start,” he said. “Virtual mini-case management conferences could also help drive innovation and reduce delay.”

Stephenson Harwood’s analysis concludes that a better-resourced and more streamlined CAT could serve as a cornerstone of the UK’s pro-competition framework. “Success,” Polonsky said, “would mean that the government had listened to the call to reverse PACCAR, allocate further resources to the CAT, and expand its remit to include other mass tort claims. A system that progresses cases at pace and proportionate cost would benefit all court users.”