High Court adjourns landmark securities class action trial due to risk of prejudice to overlapping criminal proceedings

The High Court has ordered the adjournment of a securities class action brought under s.90 and/or s.90A and Schedule 10A of the Financial Services and Markets Act 2000 (FSMA), which was listed to begin in October 2026 and would have been the first such claim to proceed to trial (previous cases having settled before trial): Aabar Holdings SARL v Glencore plc [2026] EWHC 1328 (Comm). 

The central question before the court was how the civil trial should proceed given the substantial overlap with the pending criminal prosecution. There is no rule that civil proceedings must be adjourned or stayed in favour of criminal proceedings (in order to avoid the risk of the criminal proceedings being prejudiced by overlapping issues being considered by the civil courts). However, the court must consider the risk of injustice arising in the criminal proceedings, and whether that risk can be mitigated by the imposition of sufficient safeguards in the civil proceedings.

The adjournment was ordered partly in light of restrictions sought by the Serious Fraud Office (SFO) in relation to the conduct of the trial. While the court was not persuaded that a trial subject to those restrictions would be unworkable, it accepted that they would be inconvenient and a substantial derogation from the principle of open justice. Further, there was a real risk that those restrictions would fail and prejudice the criminal proceedings in any event. 

This is a significant decision in the context of securities class actions, as the adjournment will delay the possibility of any findings against the defendant at trial. Notably, the court did not order a stay of the proceedings overall, on the basis that issues due to be dealt with at trial 2 (relating to the individual claimants' cases) could be progressed in the meantime and potentially included in a deferred trial 1. That possibility may fundamentally affect the allocation of litigation risk between the parties. 

We consider the decision in more detail below.

Background

The claimants are current or former shareholders of Glencore plc (Glencore) who commenced proceedings in September 2022 against Glencore. They brought claims under s.90 and/or s.90A and Schedule 10A of FSMA , alleging that certain prospectuses published between 2011 and 2013, and certain other published information, were misleading or contained material omissions.

At the first case management conference, the court ordered a split trial. The first trial (Trial 1), listed for 10-12 weeks from October 2026, was to address defendant-side liability issues concerning the alleged misstatements. Subsequently, the SFO brought criminal charges against certain individuals in connection with overlapping subject matter, with the criminal trial listed for October 2027, i.e. after the conclusion of Trial 1 and after judgment was likely to have been delivered. The SFO intervened in the civil proceedings and a confidentiality ring order (CRO) was established to manage the significant overlap between the two sets of proceedings. Approximately 60,000 of the roughly 260,000 disclosed documents were designated to the CRO.

In April 2026, several applications came before the court. Glencore applied for witness summonses in respect of two individuals connected to the criminal proceedings, referred to in the judgment only as A and B. The SFO sought orders concerning the conduct of Trial 1, including continuation of the CRO and restrictions on the use of documents. A and B opposed the witness summonses and applied, in the alternative, for an adjournment of Trial 1. Glencore argued that if the SFO's proposed measures were adopted, or if the witness summonses were refused, Trial 1 should also be adjourned.

Decision

The court summarised key principles in relation to: (i) the issue / challenging of witness summonses; and (ii) the stay or adjournment of civil proceedings in favour of criminal proceedings. 

Witness summonses

In relation to witness summonses, the court summarised the following principles: 

• The court's permission is not usually required to issue a witness summons (although in this case the court's permission was required). The applicable principles were summarised in Banque Havilland SA v FCA [2025] UKUT 00197 (TCC).
• There is a burden on the party seeking a summons to justify the need for it. 
• A summons will only be justified if there is "a real likelihood" that the witness would give evidence that will assist the court in its determination of an issue/issues in the proceedings. 
• A potential witness may oppose a summons on the basis that it would be unfair and oppressive for one to be issued – with the burden of proof on the potential witness. 
• What is unfair and oppressive is extremely fact sensitive and requires the court to balance all the circumstances, including the consequences for the fairness of the proceedings if the potential witness is not required to give evidence. 

Applying those principles, the court determined that there was a real likelihood that A and B could give evidence that would be of material assistance in determining the issues in the civil proceedings. The court was not persuaded by arguments that their evidence would be unnecessary or pointless (including because the facts to which they might speak would be covered by other evidence), or by arguments that the witness summonses had been made tactically by Glencore in order to necessitate the adjournment of trial (given the role of A and B in the concurrent criminal proceedings). 

However, the court considered that the pending criminal trial should clearly affect the approach to the witness summonses. The court was in no doubt that it would be unduly prejudicial to A and B to require them to give evidence at a civil hearing in advance of the criminal trial in relation to overlapping issues. That left the court with the option of either refusing the witness summonses, or adjourning the trial in order to mitigate the prejudice to the potential witnesses. 

Adjournment of trial

In relation to whether a stay or adjournment should be granted where there are concurrent civil and criminal proceedings, the court summarised the following principles: 

• There is no automatic requirement to stay civil proceedings pending conclusion of a related criminal trial. Instead, the question is a matter for the discretion of the court (per Panton and Others v Financial Institutions Services Ltd [2004] 1 LRC 768). 
• The overarching test to be applied when considering the need for a stay is whether there is a real danger of causing injustice in the criminal proceedings. 
• What constitutes a real risk of serious prejudice which may lead to injustice has to be considered on a case by case basis. The risk of injustice must be real and not merely notional. 
• If appropriate and sufficient safeguards can be imposed in the civil proceedings to mitigate or eliminate the risk of injustice in the criminal proceedings, then that is a factor that will militate against a stay. 

In these proceedings, the court determined that, even with the restrictions proposed by the SFO, there would be a real and not insignificant risk that the measures would fail, and that material could enter the public domain that would prejudice the fairness of the criminal trial (for example, as a result of the jury relying on material other than the evidence in those proceedings). 

Further the restrictions applied for by the SFO would have been inconvenient, difficult to manage and required a significant derogation from the principle of open justice (requiring the court to sit in private for as much as half of the trial and the imposition of reporting restrictions following the judgment). 

In the circumstances, the court considered it clearly preferable for the civil trial to follow the criminal trial, and therefore for the civil trial to be adjourned. It commented that the claimants would suffer limited prejudice from that delay, given the time that had already elapsed between events relevant to the claims, and proceedings being issued. Further, the adjourned trial would not in any event have led to a monetary award (this would require a second trial, which would have followed the criminal trial). 

In light of the adjournment of Trial 1, the court also adjourned Glencore's applications for witness summonses against A and B, noting that considerations in relation to those applications may be different after the criminal trial.