England cemented as key destination for arbitration

Significant developments included the introduction of new legislation to streamline and strengthen arbitration processes, notable cases which helped define and shape the direction of decisions going forward, and prominent arbitration events.

Legislative updates

The Arbitration Act 2025 (‘the Act’) came into force on 1 August, including targeted reforms aimed at modernising its 1996 predecessor and confirming the role of London as a leading seat for arbitration.

• Read more: international arbitration developments and trends for 2025-26

Among the noteworthy changes introduced were:

Governing law

The Act brought about a default rule regarding the governing law applicable to arbitration agreements. In the absence of express agreement by the parties as to the law applicable to the arbitration agreement, “the law of the seat of the arbitration in question” will be assumed to be the law of the arbitration agreement, although this does not apply to investor-state arbitration agreements formed under treaties or foreign investment legislation.

Summary disposal

The tribunal now has authority to make an award on a summary basis to dispose of claims or issues with no real prospect of succeeding. Parties wishing to opt out of the summary disposal powers granted to the tribunal can agree to disapply them, as the new power the Act introduces is not mandatory. However, if parties fail to disapply summary powers – which are similar to the courts’ powers of summary or expedited judgment in England and Wales – they will be available to the tribunal.

Emergency arbitrators

The Act gives statutory recognition to emergency arbitrators, awarding them the power to issue peremptory orders that are enforceable by the court.

Duty of disclosure

The Act confirms that arbitrators must disclose potential conflicts of interest, effectively codifying the Supreme Court’s 2020 decision in Halliburton v Chubb.

Jurisdiction challenges

The Act clarifies procedures regarding court intervention on the jurisdiction of the tribunal under sections 32 and 67, including providing for awards to be remitted to tribunals following successful s67 challenges to awards on jurisdictional grounds.

Alongside this, the UK government announced plans on 17 December 2025 to introduce legislation to resolve uncertainty in the UK third-party litigation and arbitration funding market that has existed since the Supreme Court's 2023 decision in the PACCAR case.

The move comes at a time when third-party funding of arbitration is becoming an increasingly prevalent feature of the arbitration landscape, as recognised by the Chartered Institute of Arbitrators’ publication in September 2025 of a useful Guideline on Third-Party Funding for practitioners.

It is not yet known when the proposed legislation to reverse PACCAR will be introduced to parliament.

Notable cases in 2025

Court decisions in Yukos Oil v Russia

Can a foreign court’s finding that a state has waived immunity from enforcement of an arbitral award preclude that state from asserting immunity again in the UK? The English courts answered yes, applying the doctrine of issue estoppel to prevent Russia from re-litigating an issue already decided by the Dutch courts.

The long-running enforcement battle between the former shareholders of Yukos Oil and the Russian Federation reached a critical milestone in June 2025, when the UK Supreme Court refused Russia permission to appeal a key ruling on state immunity, effectively upholding the English courts’ earlier findings that Russia is precluded from re-litigating its immunity defence in the UK.

The case stems from three arbitral awards issued in 2014 under the Energy Charter Treaty - with a combined value exceeding US$50 billion - in favour of Yukos’ former shareholders. The seat of arbitration was The Hague, and both the Dutch Court of Appeal and the Dutch Supreme Court had already ruled that Russia had consented in writing to arbitration, thereby waiving its jurisdictional immunity.

When enforcement proceedings were brought in the English Commercial Court, Russia sought to invoke state immunity under the State Immunity Act 1978 (SIA). However, the Commercial Court held that the Dutch decisions gave rise to an issue estoppel, preventing Russia from re-arguing the question of consent to arbitration, and the Court of Appeal upheld this view.

On 27 June 2025, the UK Supreme Court refused Russia’s application for permission to appeal, finding that the case did not raise an arguable point of law. Russia was also ordered to pay the respondents’ costs.

In March 2026, the English Commercial Court handed down a judgment enforcing the arbitration award, thought to be one of the largest judgments ever granted by the Commercial Court.

The case brings with it several practical implications, perhaps most notably that issue estoppel - the principle which prevents parties from re-arguing already decided issues - applies even in the context of state immunity.

This is significant because it limits the ability of states to ‘forum shop’ or re-litigate jurisdictional defences in multiple jurisdictions.

The Court of Appeal decision clarifies that while the SIA sets out exceptions to immunity, it does not displace common law rules - such as issue estoppel - that govern how those exceptions are applied. This preserves the flexibility of English courts to manage complex cross-border enforcement disputes.

The ruling also reinforces the respect and weight given to foreign judgments, particularly from the courts of the seat of arbitration. It affirms that English courts will not lightly revisit issues already determined by competent foreign courts, especially where the seat has a close connection to the arbitration.

For investors pursuing enforcement against states, this decision is a major win. It reduces the risk of protracted jurisdictional challenges and supports the finality and enforceability of arbitral awards. It also underscores the importance of choosing a reputable and arbitration-friendly seat.

Commercial Court’s decision in CC/Devas and others v Republic of India

The Commercial Court reaffirmed state immunity as a core principle of international law in ruling that ratification of the New York Convention did not amount to an unequivocal submission to the jurisdiction of national courts.

The decision arose from a long-running dispute after a 2005 contract between Devas Multimedia and India’s state-owned Antrix Corporation, the commercial arm of its space research organisation. Devas had agreed to lease S-band spectrum from Antrix to broadcast in India before the contract was terminated in 2011 under national security concerns, with Devas and its partners winning arbitration awards afterwards, and beginning enforcement proceedings in various territories.

The court emphasised that any waiver of immunity must be express and unambiguous, and that there is no language in the New York Convention which waives immunity from adjudicative jurisdiction. It highlighted the difference in this instance from the Court of Appeal’s decision in Infrastructure Services v Spain, below, where ratification of the ICSID Convention was held to constitute a “prior written agreement” under s2(2) of the SIA, as that convention contains more explicit provisions regarding enforcement and jurisdiction.

Supreme Court's decision in Infrastructure Services Luxembourg S.à r.l. and others v Kingdom of Spain

In March 2026 the UK Supreme Court confirmed that countries that have signed the ICSID Convention thereby waive their rights to claim state immunity in the UK against the enforcement of ICSID awards against them before the UK courts.

Foreign investors in Spain and Zimbabwe had secured ICSID awards against the two states and sought to register them as English judgments for enforcement purposes. The states sought to set aside the registration orders on the grounds of state immunity.

The Supreme Court had to consider whether signing of the ICSID Convention constituted a waiver of rights to state immunity for the purposes of the SIA. Article 53(1) of the ICSID Convention provides that each contracting state shall recognise an award as binding and enforce the award within its territories as if it were a final judgment of a court in that state.

The Supreme Court, agreeing with the Court of Appeal, said that states’ agreement to article 54(1) demonstrated “a clear and unequivocal expression of the state’s consent to the exercise of jurisdiction” and that this was “a matter of ordinary language”.

The decision removes a major procedural obstacle that states have increasingly sought to deploy at the enforcement stage in relation to ICSID awards, giving investors greater confidence that ICSID awards will be capable of recognition in England without being stalled by immunity arguments, and bringing the jurisdiction into alignment with Australia, New Zealand, the US and Malaysia.

Court of Appeal decision on anti-suit relief in Star Hydro Power Limited v National Transmission and Despatch Company Ltd

In a significant judgment, the Court of Appeal unanimously granted an anti-suit injunction to restrain proceedings brought in Pakistan that sought to challenge a London-seated arbitral award.

The decision reinforced English courts’ exclusive supervisory jurisdiction over arbitrations seated in London, and offered guidance on the limits of court intervention overseas on these kinds of proceedings.

It came after a London-seated arbitration between Star Hydro Power and Pakistan’s state-owned National Transmission and Despatch Company. Following the issuance of an arbitral award, NTDC initiated proceedings in Lahore, Pakistan, seeking to challenge the award.

Star Hydro applied to the English courts for an anti-suit injunction, arguing that the Pakistani proceedings were an impermissible attempt to undermine the supervisory role of the English courts under the Arbitration Act 1996 - now amended by the Arbitration Act 2025.

The Court of Appeal ruled that English courts have exclusive authority to supervise and determine challenges to awards rendered in arbitrations seated in London. This is a fundamental principle of the ‘seat theory’ in international arbitration. However, although the New York Convention governs the recognition and enforcement of foreign arbitral awards, it does not authorise pre-emptive challenges to awards in jurisdictions other than the seat.

The Convention is designed to protect awards, not provide a basis for undermining them, and the Court of Appeal found that NTDC’s proceedings in Pakistan were an attempt to pre-emptively challenge the award outside the supervisory jurisdiction of the seat. This was a clear breach of the parties’ agreement to arbitrate in London and justified the grant of an anti-suit injunction.

The judgment underscores the continued availability and effectiveness of anti-suit injunctions in England to protect the integrity of arbitration agreements and awards. It sends a clear message that English courts will act decisively to prevent foreign proceedings which threaten the finality of awards rendered under their supervision.

The judgment is also particularly important in clarifying that the New York Convention does not create a right to challenge awards in non-seat jurisdictions, reinforcing the limited scope of foreign court intervention.

Parties choosing London as the seat of arbitration can take comfort in the strong protective stance of the English courts. However, they should also ensure that their arbitration agreements are clearly drafted and that they are prepared to act swiftly to seek injunctive relief if enforcement is threatened by foreign proceedings.

The decision is currently the subject of an appeal to the UK Supreme Court.

Confirmation of English courts’ powers to enforce a tribunal’s peremptory orders

In LLC Eurochem North-West-2 v Tecnimont SPA & Anor, the Court of Appeal dismissed an appeal seeking to challenge the English court’s power under s42 of the Arbitration Act 1996 to enforce peremptory orders made by a London-seated ICC tribunal.

The tribunal had made the peremptory orders following breaches of earlier procedural orders, in order to restrain proceedings commenced by the respondent in Russia.

The Commercial Court was asked to enforce the tribunal’s peremptory orders and granted anti-suit relief.  The respondent appealed to the Court of Appeal, arguing that the court granting such relief was not “necessary for the proper and expeditious conduct of the arbitration” as required by the 1996 Act.

The Court of Appeal rejected the appeal, finding that a tribunal can make a peremptory order for any failure to comply with its orders or directions, and that compliance with an order of a tribunal acting within its powers will always be capable of being “necessary for the proper and expeditious conduct” of an arbitration.

The Court of Appeal said that, in any event, anti-suit relief of the type granted in this case was capable of being necessary for the proper and expeditious conduct of the arbitration.

The decision reinforces the power of the English courts to make orders to protect arbitration against parallel proceedings which are contrary to the parties’ agreement to arbitrate and threaten to undermine the arbitral process.

Industry insights and events

Findings from the Law Society underline that England and Wales continue to lead as a global destination commercial litigation and arbitration, with London at the heart of this activity, particularly in areas such as maritime arbitration, where the city remains the global leader – with 1,733 new cases handled by the London Maritime Arbitrators Association in 2024.

English law continues to be the preferred governing law in international arbitration. Notably, 78% of London Court of International Arbitration (LCIA) cases were governed by English law in 2024, while it was the most commonly used law for new cases handled by the International Chamber of Commerce (ICC) Court of Arbitration. It was also second most common for cases administered by Arbitration Institute of the Stockholm Chamber of Commerce, Singapore International Arbitration Centre and Hong Kong International Arbitration Centre, emphasising the importance of English law in dispute resolution.

London also remains the most preferred seat for arbitration globally, with 34% of respondents choosing London as their preferred seat in Queen Mary University’s 2025 International Arbitration Survey, which sits ahead of Paris, Geneva and New York as a chosen seat for ICC cases.

The LCIA continues to be a truly international institution, with 95% of the body’s arbitrations involving at least one international party, and 75% involving only international parties with no UK representation. As many as 85% of parties were from jurisdictions outside the UK. London was the chosen seat in 89% of LCIA arbitrations, with the figures continuing to reflect confidence in the jurisdiction’s legal infrastructure and neutrality.

Interestingly, there is also a growing trend of public sector entities turning to LCIA arbitration, with state-owned entity or state-involved cases up from 11% in 2023 to 14% the following year.

In terms of sector, transport and commodity cases made up the largest proportion of those administered by the LCIA at 29% of cases, followed by banking and finance at 17%, with a further 10% coming from energy cases.

While London and English law dominated the LCIA’s caseload, there has been a notable shift with parties increasingly choosing diverse legal systems and seats, reflecting the institution’s adaptability and global appeal. Arbitrations were administered across 21 seats in 15 jurisdictions, governed by 35 substantive laws from 32 jurisdictions.

London International Disputes Week 2025 LIDW25 marked a pivotal moment for London’s standing as a global centre for international dispute resolution. Set against a backdrop of geopolitical uncertainty, shifting regulatory frameworks and rapid technological transformation, the theme – “Innovation in Dispute Resolution: Navigating Global Risks” – resonated strongly. With more than 10,000 attendees, including 1,708 international participants, the event confirmed London’s enduring appeal as a hub for cross-border legal dialogue and collaboration.

As a founding member firm of LIDW, Pinsent Masons supported the development of the event’s International Arbitration Day (IAD), with Scheherazade Dubash serving on the LIDW Strategy Group and organising committee for IAD. Pinsent Masons experts including Sylvia Tonova, Dr Dean Lewis, Jim Cormack KC, James Cameron and Edward Shaw spoke at panels and led sessions on topics ranging from the interplay between European legal frameworks and the ICSID Convention, to co-counselling and good faith. Finally the LIDW Main Conference, for an audience of around 700 in-person delegates from around the world, saw high-profile speakers from the international arbitration and wider dispute resolution community take the stage, with the organisation of this day led by Emilie Jones of Pinsent Masons.

A number of these themes will be explored at the upcoming LIDW26 in June, for which Jones acts as one LIDW’s co-chairs and Dubash continues in her role shaping the IAD.

Pinsent Masons also played a key role in the inaugural London Arbitration Week – a week of events dedicated specifically to exploration of topics relevant to international arbitration – in December.

Co-written by Emilie Jones of Pinsent Masons