No issue estoppel preventing challenge to enforcement of arbitration award on ground of state immunity

Yukos Capital Ltd v The Russian Federation [2026] EWHC 1918 (Comm) (17 July 2026)

We have previously reported on related proceedings involving allegations by the former majority shareholders in OAO Yukos Oil Company that the Russian Federation (Russia) had breached its obligations under the Energy Charter Treaty (ECT) 1994. The claimants in those proceedings obtained ECT arbitration awards in their favour, which they sought to have recognised and enforced in England and Wales pursuant to s.101 Arbitration Act 1996 (1996 Act). Russia sought to avoid enforcement of those awards on the ground of state immunity.

In one decision, the Court of Appeal dealt with issue estoppel in relation to findings by the Amsterdam Court of Appeal that, contrary to Russia’s case, there was a binding arbitration agreement: see Issue Estoppel and State Immunity: Arbitration | Hill Dickinson. The English Court of Appeal held that Russia could not reargue an issue before the English Court that had already been decided on and dismissed by the foreign court.

In a later decision, the English Commercial Court dismissed Russia’s public policy defence to the recognition and enforcement of the awards against it: see Court dismisses public policy defence to enforcing Energy Charter Treaty awards.

This is the latest chapter in Russia’s attempts to resist the enforcement of ECT arbitration awards made against it.

The background facts

In July 2021, Yukos Capital Ltd (Yukos) obtained an arbitral award in its favour against the Russia for breaches of the ECT 1994. The arbitration was seated in Switzerland.

Russia applied for an order from the Swiss courts to set aside the award. The Swiss Court dismissed the claim on all grounds that Russia had relied upon in those proceedings.

Further to an application made in November 2023, in March 2024, Yukos obtained an order from the English Court for recognition and enforcement of the award under s.101 of the 1996 Act. Russia then sought to have that order set aside on the ground that it had state immunity.

The Court considered, as a preliminary issue, whether the Swiss court decision gave rise to any cause of action estoppel and/or any issue estoppel that precluded Russia from denying that it had agreed in writing to submit to arbitration the dispute that was the subject of the final award.

The arguments

Yukos argued that Russia could not rely on state immunity under s.1(1) of the State Immunity 1978 because it had agreed to submit the dispute the subject of the award to arbitration, thereby engaging the exception to immunity conferred by s.9 of the 1978 Act. The jurisdiction issue had been determined finally and conclusively in Yukos’ favour by the Swiss Court in the set-aside proceedings. There was therefore either a cause of action estoppel or an issue estoppel as a matter of English law, which precluded Russia from rearguing the jurisdiction issue before the English Court.

Russia said there was no cause of action estoppel because the Swiss proceedings were not concerned with either the recognition or enforcement of the award in England. Further, there was no issue estoppel doctrine under Swiss law that would preclude Russia from re-arguing the same issue in Switzerland. There was also no issue estoppel in respect of issues not argued before the Swiss courts or that were declared inadmissible because there had been no determination on the merits in relation to those issues.

The Commercial Court decision

Cause of action estoppel

Having heard expert evidence on Swiss law, the Court decided there was no cause of action estoppel because the rights and remedies sought in the Swiss proceedings were not the same as those sought in the English proceedings. In Switzerland, Russia sought to have the award set aside under Swiss private international law. In England, Russia sought an order that it was entitled to state immunity under the 1978 Act.

Issue estoppel

Issue estoppel arising from judgments of foreign courts must satisfy four conditions:

1. the judgment must be given by a foreign court of competent jurisdiction

2. the judgment must be final and conclusive on its merits

3. there must be an identity of parties, and

4. the issue to be determined by the foreign court must be the same as that arising in the English proceedings.

In this case, (1) to (3) were satisfied. As to (4), the Court had to consider:

1. what constituted an ’issue’

2. whether the issue or issues in the immunity proceedings was or were exactly the same as those decided in the Swiss proceedings, and

3. whether those issues were necessary rather than incidental.

The Court decided that insofar as issue estoppel might be available, it could only apply to the three limited issues that the Swiss Court decided on their merits. It did not apply to grounds that could have been, but were not, argued in the Swiss proceedings. Whether the latter amounted to an abuse of process was not something the Court needed to consider in this case, although it highlighted that it could potentially have a preclusive effect.

Further, having heard Swiss law expert evidence that there was no doctrine of issue estoppel in Swiss law, the Court concluded that there could be no issue estoppel by reference to the reasoning in the Swiss judgment.

This decision does not mean that Russia has succeeded in preventing the recognition and enforcement of the award. The Court still has to consider the state immunity defence at trial and whether the position adopted by Russia is abusive in the Henderson -v- Henderson sense.

Comment

As the Court highlighted, caution is required when considering issue estoppel based on a foreign judgment because the procedures of the foreign court may be different and it may not be easy to determine the precise identity of issues being decided upon.

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