A Class Act: Is England a New Battleground in High-Value Multi-Claimant Actions?

Dechert has continued to follow recent developments in English law that have attracted mass tort and multi-claimant litigation.¹ Since 2022, multi-claimant litigation in England has surged, particularly in proceedings brought in the CAT, which have increased by almost 200 percent, from 15 actions filed between 2015 and 2021 to 44 actions since 2022.² GLO actions have also expanded: in just the past two years, courts approved 14 GLOs, while in the six years between 2015 and 2021, courts approved just 16 GLOs.³ High-value claims relating to data breaches, environmental, social, and governance (“ESG”), and product liability claims, among others, are increasingly being filed, with a wide spectrum of claims being certified in the CAT that push the boundaries of traditional competition law subject matter.

As with the United States, England has multiple mechanisms for multi-claimant litigation. While the mechanisms in the United States are deeply entrenched, in recent years, plaintiffs in England have explored different types of multi-claimant actions, as U.S.-style mass litigation has become increasingly more common. Litigants and courts have grappled with the viability of the different mechanisms for bringing these actions with mixed results.

CPR Representative Actions: “Same Interest” Test Could Doom Multi-Claimant Actions

CPR representative actions, one type of collective redress in England, generally allow a representative claimant to bring a claim on behalf of individuals with the “same interest,” similar in some ways to the U.S. federal class action regime. Since the Supreme Court decision in Lloyd v Google in 2021, meeting the “same interest” test has been a significant barrier for English litigants, as it requires that claims be sufficiently uniform to proceed on a representative basis.⁴

However, some litigants have been undeterred by Lloyd v Google, and in 2023, in Commission Recovery v Marks & Clerk, the High Court allowed a representative action to proceed despite the individuals bringing varied claims and seeking different remedies.⁵ The Court of Appeal upheld the decision in January 2024,⁶ distinguishing between (i) impermissible conflicts of interest—where advancing some class members’ claims would prejudice others; and (ii) acceptable divergent interests—where an issue affects only some class members but does not prejudice others. 

While some may argue that the Marks decision suggests that representative actions could address complex group claims, attempts to use CPR representative actions in this way continue to face judicial roadblocks. Courts remain reluctant to bifurcate trials—e.g., by splitting liability and damages phases—to satisfy the “same interest” test.⁷ Our recent OnPoint article on the Wirral case – in which the Court of Appeal rejected the use of a bifurcation procedure for a CPR representative action on the basis of the availability of multi-party proceedings as an alternative procedure – can be found here.

CAT Actions: Developing Practices at the CAT Welcome New Claims, While Focusing on Flexibility, Fairness, and Scrutiny

Though there has been mixed success under Part 19 of the CPR (which covers both CPR representative actions and GLOs), multi-claimant actions brought in the CAT have increased significantly in England over the last few years. The CAT, which has heard an increasingly expansive array of competition law-related cases, including consumer rights, allows classes to be certified on an opt-out basis (akin to U.S.-style opt-out class actions). Originally introduced as a mechanism for private “follow-on” damages claims relating to cartels and behavioral competition law infringements, the opt-out mechanism has become the weapon of choice for extremely high-value alleged claims (particularly against big tech companies) with claimants pursuing damages often in the hundreds of millions and tens of billions of pounds.

In 2015, the CAT was empowered to hear opt-out multi-claimant actions,⁸ and in 2021, the CAT certified the first opt-out collective proceedings order (“CPO”) in Merricks v Mastercard,⁹which led to the proliferation of opt-out CAT actions. Then, a 2023 Court of Appeal decision clarified that the collective action regime in the CAT can be utilized by businesses in addition to individual consumers.¹⁰ The CAT has also allowed claimants to address deficiencies in their claims and submit additional evidence, rather than rejecting certification outright.¹¹

New approaches to bringing non-traditional competition claims are also emerging, such as plaintiffs framing business activity related to ESG claims¹² and data usage¹³ as “abuse of a dominant position.” So far, the CAT has been open to hearing these non-traditional competition claims.

Despite these trends, the CAT has demonstrated a more critical eye at later evidentiary stages. In December 2024, the CAT issued a defense ruling in the first opt-out collective action to proceed to a full trial and reach a substantive judgment. In Le Patourel v BT, the CAT unanimously dismissed the £1 billion collective action following a rigorous assessment of the legal arguments and complex expert evidence.¹⁴ The ruling underscores the CAT’s proactive engagement and “hands-on” approach to resolving complex disputes. In addition, unlike in the U.S. class action system, such trials in England are decided by a tribunal (composed of a judge and two “ordinary members”) rather than juries. 

Over the past two years, the CAT approved its first-ever settlements in opt-out claims, issuing opinions focused on “reasonableness” and “fairness.” The first settlement judgment in December 2023, for £1.2 million, emphasized proportionality, cost-effectiveness, and the need to avoid protracted litigation.¹⁵ The second settlement judgment in May 2024, for £25 million, focused on ensuring that the settlement was “just and reasonable.”¹⁶ More recently, in December 2024, the CAT approved settlements in a car delivery class action worth £37.3 million total against two defendants.¹⁷

Criticisms of the rapidly evolving CAT process include a lack of viable settlement mechanisms between class certification and evidentiary/merits phases. With such a low bar to certifying claims and no formal intermediary “summary judgment” phase as in the United States, companies have found it hard to triage and settle poor quality claims before the full merits and disclosure stages. This means that companies are at risk of having their sensitive operational and strategic information laid bare in public, with fewer procedural levers available to settle less robust claims post-certification compared to the United States. 

GLOs: Courts Seek Efficiency in Collective Individual Case Management

Unlike the opt-out system under the collective action regime in the CAT, GLOs operate on an opt-in basis, requiring claimants to actively join the action before the court can manage their cases.¹⁸ GLOs resemble U.S. multidistrict litigations (“MDLs”) in that both allow a court to coordinate numerous individual claims, with one judge handling case management and discovery. This opt-in requirement continues to make GLOs less common than CAT actions, as claimants must bear the administrative burden of proving their individual cases. However, recent judicial trends indicate a shift toward more flexible and efficient case management, which may encourage more GLO applications. This evolving approach is exemplified in the ongoing Pan-NOx (nitrogen oxides) emissions litigation, where the High Court is managing numerous GLOs against car manufacturers under a unified framework.¹⁹ The High Court has streamlined proceedings by designating lead and backup cases, with the objective of ensuring consistency in case management, and addressing the inherent challenges of scale, complexity, and cost in mass claims. The Mercedes GLO, selected as the “Lead GLO” for being the most advanced, is scheduled for trial in October 2025.²⁰ This trial, along with three additional Lead GLOs, will serve as test cases to resolve common legal and factual issues across the broader emissions claims and streamline the resolution of the remaining claims. 

As another example of flexible approaches, in a 2023 GLO formation judgment, the High Court referenced the notion of a “GLO Lite,” a more informal mechanism for coordinating group actions without the full procedural demands of a traditional GLO.²¹ Unlike a formal GLO, a GLO Lite would not require a court order, a group register, or a cut-off date for claimants to join, and findings on common issues would not automatically bind all parties.²² While the process offers flexibility, its practical implementation remains unclear.

These developments highlight the growing viability of GLOs for large-scale litigation, demonstrating the courts’ willingness to modernize a previously cumbersome and limiting procedural device.

Conclusion

Multi-claimant litigation in England has seen significant changes, across a range of species of civil claim mechanisms, including CPR representative actions, CAT actions, and GLOs. While they share similarities with U.S. class actions and MDLs, in many ways these mechanisms are still in their adolescence in the English legal system. CPR representative actions face judicial and procedural hurdles, but the CAT—with relatively new opt-out rules and expansive certification—has increasingly become a forum for high-value collective claims. At the same time, the High Court’s efforts to streamline GLOs and consider the “GLO Lite” mechanism reflect a commitment to updating aspects of its collective litigation procedures. English law continues to evolve in managing complex mass tort and multi-claimant cases, presenting both opportunities and challenges.