It is set to be another busy year for group actions with key cases progressing through the courts and CAT. Stay informed with the top cases we will be watching in 2026. 

Glencore securities action

The trial on liability issues in the large-scale group action brought by hundreds of claimants against Glencore (among others) under sections 90 and 90A of the Financial Services and Markets Act 2000 is listed for October 2026 in the Commercial Court. This case is set to be the second securities group action to reach trial, with the first being Serco, which settled during the trial on liability issues. The only previously decided claim under section 90A FSMA was that brought by HP following its acquisition of Autonomy. Clifford Chance acted in both the Serco and HP cases, and acts for Glencore in this securities action.

Appeal in Kent v Apple and Neil v Sony trial

Kent v Apple was a landmark decision of 2025, being the first competition collective action to succeed at trial with the CAT concluding that Apple had abused its dominant position. including by charging excessive and unfair prices in the form of the Commission that it charges developers for iOS app distribution services and iOS in-app payment services. While Apple was refused permission to appeal in the CAT, in 2026 we expect to see Apple seeking permission to appeal to the Court of Appeal, as Apple noted it strongly disagreed with the ruling. We also await in 2026 to see how the CAT deals with the trial of Neil v Sony commencing in March, which concerns allegations that Sony's conditions and pricing practices on the PlayStation Store have caused loss and damage to users.

Liability judgment in ‘Pan-NOx’ emissions scandal

It will be another busy year in the Pan-NOx emissions litigation. The claimants allege that more than a dozen vehicle manufacturers used illegal ‘defeat devices’ to cheat emissions tests undertaken by regulators. The claim, reportedly brought on behalf of more than 1.8 million claimants seeking damages of over £6 billion, involves 13 separate Group Litigation Orders, emphasising the size and scale of this litigation.

The liability trial which focused on the prohibited defeat devices, commenced in mid-October and ran until mid-December 2025. The parties will reconvene for closing submissions in March 2026. A second-stage trial focusing on issues of causation and loss is currently scheduled to start in October 2026 (if required).

River Wye pollution claim

The UK’s largest environmental group litigation continues into 2026, with nearly 4,000 claimants pursuing claims against Avara Foods, Freemans of Newent and Welsh Water over alleged nutrient and sewage pollution in the River Wye catchment. The claim, which includes allegations of nuisance, negligence and breaches of environmental law, seeks substantial damages and a court-mandated clean-up. Following the filing of the claim in October 2025, the defendants deny liability and are expected to file their defences in early 2026.

A trial timetable has yet to be set, but the case could have significant implications for future environmental group actions.

High Court decision in military deafness litigation

2025 ended with a key trial in the military deafness litigation where the High Court heard a selection of lead claimants’ cases against the Ministry of Defence, focusing on causation and damages. Notably, four high-value claims were settled before the trial began. The lead claimants already represent more than 11,000 claimants who allege they suffered noise induced hearing loss during their military service. That number continues to grow with the Ministry of Defence recently agreeing to extend the registration period until the end of July 2026. If the High Court confirms the six-month extension, the parties will likely have the opportunity to consider claims in light of the causation and damages judgment, which is expected in Spring 2026.

Relatedly, reports suggest a separate product liability claim is being initiated against the manufacturer of the allegedly defective ear protection products that were supplied to the Ministry of Defence.

Second-stage trial in Municipio de Mariana v BHP Group

Following the landmark liability judgment in 2025 which held that UK‑domiciled parent company, BHP Group (UK), was liable in relation to operations associated with its Brazilian subsidiary in Brazil, we will be closely monitoring the next phase of the BHP Mariana Dam group litigation. BHP has been denied permission to appeal the liability judgment in the first instance but may seek permission from the Court of Appeal. In the meantime, the second stage quantum trial to determine recoverable damages is listed to begin in October 2026, with the claimants seeking up to £36 billion in damages. The High Court will also address how prior Brazilian compensation schemes and settlements affect the remaining claims.

Le Patourel v Apple and Amazon

We will be closely following round two of the claim against Apple and Amazon, which alleges that an agreement restricting the number of Apple resellers on Amazon distorted competition in the UK and led to inflated prices. In 2025, the CAT refused to certify the same claim brought by Professor Riefa, on the basis that she was not a suitable class representative. We await to see if Le Patourel's replacement of Professor Riefa will allow the certification hurdle to be cleared.

Merricks v Mastercard judicial review

By far the most contentious of the collective actions so far resolved by settlement has been the settlement in Merricks v Mastercard for £200 million when certification was obtained for a claim worth c. £9-10 billion. Innsworth, the funder has now brought judicial review proceedings of the CAT's decision after a public disagreement regarding the return Innsworth received from the settlement. This may inform funders' risk assessments in future claims and prove a cautionary tale for potential class representatives when considering their funding arrangements.