United Kingdom
Most commonly, groups of litigants whose claims give rise to common or related issues of fact or law will combine their actions under a Group Litigation Order, although this is more a tool for efficient case management than a true collective action. Private damages actions for breach of competition law were bolstered in December 2020 by a decision of the UK Supreme Court in Mastercard v Merricks, leading to that case becoming the first to be certified by the Competition Appeal Tribunal as appropriate to be brought by way of opt out collective proceedings. However, the future of representative actions for data breach claims has suffered a setback following the Supreme Court's decision in Lloyd v Google.