Litigation Radar: River Wye pollution group action, Nord Stream €403m trial & Slack versus Microsoft
Key litigation updates this week include Nord Stream’s insurance battle in court, Slack’s competition claim against Microsoft, the River Wye environmental group action and major pandemic-era and military hearing loss litigation.
Published fortnightly, our Litigation Radar highlights new claims and ongoing court activity across the cases shaping the litigation landscape. This edition highlights major high-profile commercial and group litigation, including Nord Stream’s €403 million claim insurance dispute arising from the 2022 pipeline explosions, a landmark environmental group action concerning River Wye pollution and Slack’s competition claim against Microsoft over the bundling of Teams. Also featured are the Military Deafness Litigation judgment, a £40 million insurance dispute linked to failed consumer law firms and a fresh pandemic-era PPE claim brought by the UK Government.
Law firms featured:
Herbert Smith Freehills Kramer LLP • Clyde & Co LLP • Slaughter and May • Leigh Day Ltd • Pinsent Masons LLP • Kennedys Law LLP • Hugh James LLP • Keoghs LLP • DWF LLP • Simmons & Simmons LLP • Holman Fenwick Willan LLP
CL-2024-000094: Nord Stream AG v Lloyd's Insurance Company S.A. and another
Nord Stream is seeking €403 million from its insurers, Lloyd’s Insurance and Arch Insurance, in a dispute arising from the 2022 Nord Stream pipeline explosions. The insurers deny liability, arguing that the incident falls within the war-related exclusions policy. The trial, presided over by Dame Clare Moulder, is currently underway, having commenced mid-April.
CL-2026-000250: Slack Technologies LLC and others v Microsoft Corporation and others
Workplace communication platform Slack has initiated a competition claim against Microsoft arising from the alleged bundling of Microsoft Teams with other Microsoft products. The proceedings follow Slack’s 2020 complaint to the European Commission concerning alleged anti-competitive conduct and abuse of market position.
[2026] EWHC 941 (KB): Abbott and others v Ministry of Defence
Judgment has been handed down in the Military Deafness Litigation, a test-case group action in which military personnel brought claims against the Ministry of Defence alleging negligence and breaches of statutory duty arising from workplace noise exposure that caused hearing loss. The claim succeeded in part, with the court awarding compensation to the claimants.
KB-2025-003040: Ms Justine Evans and others v Avara Foods Ltd and others
A landmark environmental group action has commenced in the High Court, with thousands of claimants bringing proceedings against Avara Foods and Welsh Water. The claimants allege that pollution of the River Wye has been caused by agricultural runoff, including chicken manure from linked farms. The proceedings are at an early procedural stage, with the late-April hearing to determine case management issues, including the litigation timetable and deadlines for additional claimants to join.
CL-2025-000417: AmTrust Specialty Ltd v Endurance Worldwide Insurance Ltd (trading as Sompo International) and parties listed in schedule A
ATE insurer AmTrust, who insured unsuccessful claims run by Pure Legal and High Street Solicitors, are suing the original insurers of those law firms (as a third party to policyholder claims) for £40 million plus.
CL-2026-000220: Secretary of State for Health and Social Care v Uniserve Ltd
The Secretary of State for Health and Social Care is suing a PPE gown supplier for £90.2 million, alleging defective goods (the supply of 11 million gowns) during the Covid-19 pandemic. Just last year, the Government won a £122 million pandemic case against PPE Medpro over faulty PPE.
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