Factual and Procedural Background
This judgment concerns two combined appeals about whether two foreign states (the “appellant states”) could invoke sovereign immunity to set aside High Court registration of adverse awards made under the ICSID Convention and registered under the Arbitration (International Investment Disputes) Act 1966 (the “1966 Act”). The appeals concerned immunity from adjudicative jurisdiction only (not immunity from execution).
Appeal involving State A: Company A (two corporate investors) brought ICSID arbitration under a multilateral investment treaty after regulatory changes allegedly harmed their renewable energy investment. An ICSID award (later rectified) granted monetary compensation. State A pursued ICSID rectification and annulment; the annulment application failed and an enforcement stay was lifted. Company A applied without notice to register the rectified award in the High Court under section 1 of the 1966 Act; the award was registered as if a final High Court judgment. State A then applied to set aside registration, relying on state immunity under section 1(1) of the State Immunity Act 1978 (the “SIA 1978”). Judge Fraser dismissed that application, holding (so far as relevant) that State A had submitted to UK jurisdiction under SIA 1978 section 2(2) via the ICSID Convention (and also addressed SIA 1978 section 9(1) in the alternative). State A appealed.
Appeal involving State B: Company B (two corporate investors) brought ICSID arbitration under a bilateral investment treaty alleging expropriation without compensation. State B disputed tribunal jurisdiction, contending the treaty did not apply to the claimed “investments”/“investor” and thus no consent to arbitrate existed. The ICSID tribunal rejected the jurisdiction objection and made a monetary award; State B’s ICSID annulment application failed and a stay was refused. Company B applied without notice to register the award under section 1 of the 1966 Act; the High Court registered it as if a final High Court judgment. State B later applied to set aside registration on SIA 1978 section 1(1) immunity grounds. Judge Dias dismissed the application, holding (among other matters) that registration engaged no adjudicative jurisdiction (a conclusion later rejected by the Court of Appeal). State B appealed.
The Court of Appeal heard both appeals together and dismissed them. It held that registration under section 1 of the 1966 Act engages adjudicative jurisdiction (unchallenged before the Supreme Court). It further held that ICSID Convention article 54(1) amounts to a prior written submission to UK jurisdiction for SIA 1978 section 2(2). In State B’s case, it remitted the matter for directions on reserved non-immunity defences. The appellant states appealed to the Supreme Court.
Legal Issues Presented
- Whether, by agreeing to be bound by ICSID Convention article 54(1), the appellant states submitted to the jurisdiction of UK courts by prior written agreement within SIA 1978 section 2(2), such that they could not rely on adjudicative immunity to resist registration of ICSID awards under section 1 of the 1966 Act.
- Whether the appellant states agreed to arbitrate with the respondent investors within SIA 1978 section 9(1) (raised but not determined by the Supreme Court because it decided issue 1 was dispositive).
Arguments of the Parties
Appellant States' Arguments
- Any treaty waiver/submission displacing state immunity must be “express” in a strict sense; absent explicit words such as “waiver” or “submission,” there was no valid waiver under SIA 1978 section 2(2).
- At most, ICSID Convention article 54(1) obliged contracting states to create or provide domestic mechanisms for recognition/enforcement, but did not constitute a submission to the courts of other contracting states.
- Even if other states assumed obligations under the ICSID Convention, that did not entail the appellant states’ submission to foreign adjudicative jurisdiction; jurisdiction and immunity are distinct concepts.
- The ICSID system could still function without a waiver of adjudicative immunity (including via operation in a state’s own courts, in some third states depending on domestic immunity rules, and via inter-state mechanisms under ICSID Convention article 64).
Respondent Investors' Arguments
- “Express” submission does not require the literal use of terms like “waiver,” “submission,” or “immunity”; it is sufficient if, applying Vienna Convention articles 31–32, the treaty words clearly and unequivocally entail consent to jurisdiction.
- On proper construction of ICSID Convention articles 53–55, article 54(1) necessarily entails that each contracting state accepts that other contracting states’ courts will recognize and enforce awards against it as if final judgments, which is incompatible with retaining adjudicative immunity at the recognition/enforcement stage.
Table of Precedents Cited
| Precedent |
Rule or Principle Cited For |
Application by the Court |
| Micula v Romania [2020] UKSC 5, [2020] 1 WLR 1033 |
ICSID scheme is “self-contained”; domestic courts may not re-examine merits or refuse enforcement on public policy; limited scope for exceptional defences analogous to final judgments. |
Used to explain the ICSID enforcement structure, mutual obligations, and why recognition/enforcement obligations under article 54(1) are inconsistent with adjudicative immunity. |
| Jurisdictional Immunities of the State (Germany v Italy) (2012) ICJ Rep 99 |
State immunity derives from sovereign equality; exceptions are departures and must be justified. |
Provided background on the nature and rationale of state immunity and that treaty-based reciprocal jurisdiction can constitute waiver. |
| R v Bow Street Magistrate, Ex parte Pinochet (No 3) [2000] 1 AC 147 |
Discussion of when treaty obligations are incompatible with immunity; dissent (Lord Goff) on “express” waiver; majority reasoning on immunity and treaty purpose. |
The court rejected an unduly narrow view of “express waiver” associated with the dissent; relied on majority-style reasoning that treaty terms can clearly and unequivocally displace immunity by necessary consequence. |
| Argentine Republic v Amerada Hess Shipping Corporation (1989) 109 S Ct 683 |
Referenced in Lord Goff’s discussion of waiver by treaty under international law. |
Distinguished as not supporting a rigid requirement for explicit “waiver” wording in all contexts. |
| Argentine Republic v Amerada Hess Shipping Corporation (1989) 488 US 428 |
No implicit waiver from treaties that contain no reference to waiver or US cause of action, given their subject matter. |
Used to show the limits of inferring waiver from unrelated treaty objectives; not analogous to ICSID article 54(1)’s direct recognition/enforcement obligation. |
| NML Capital Ltd v Republic of Argentina [2011] 2 AC 495 |
A clause can constitute a clear waiver/submission without using the words “waiver” or “submission.” |
Supported the conclusion that “express” consent may arise from the ordinary meaning of words, even without specific immunity terminology. |
| [2009] EWHC 110 (Comm), [2009] QB 579 |
First-instance construction of bond clause as submission/waiver (background to NML). |
Described in the narrative leading to the Supreme Court’s approach in NML. |
| [2010] EWCA Civ 41, [2011] QB 8 |
Court of Appeal’s contrary construction in NML (background). |
Not followed; Supreme Court’s NML approach adopted. |
| General Dynamics United Kingdom Ltd v State of Libya [2025] EWCA Civ 134, [2025] 4 WLR 34 |
No added “clear words” gloss beyond construing whether consent is expressed; analysis applies similarly to SIA 1978 sections 13(3) and 2(2). |
Endorsed to confirm the court’s approach that “express” consent means clear and unequivocal on proper construction, not requiring magic words. |
| Modern Engineering (Bristol) Ltd v Gilbert-Ash (Northern) Ltd [1974] AC 689 |
Presumption about not giving up valuable rights/remedies absent clear wording (as cited in General Dynamics). |
Not adopted as a gloss on SIA 1978 section 2(2); the court preferred direct statutory construction. |
| Triple Point Technology Inc v PTT Public Co Ltd [2021] UKSC 29; [2021] AC 1148 |
Construction principle about surrender of valuable rights (as cited in General Dynamics). |
Not treated as imposing an additional express-wording threshold under SIA 1978 section 2(2). |
| R v Lama [2014] EWCA Crim 1729, [2017] QB 1171 |
Supports understanding of Pinochet (No 3) reasoning on treaty provisions and immunity. |
Cited to reinforce the court’s reading of Pinochet (No 3) as permitting displacement of immunity by necessary consequence of treaty obligations. |
| Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovina v Serbia and Montenegro) Judgment [2007] ICJ Rep 43 |
Deriving necessary implications from express treaty obligations (obligation to prevent implies prohibition on committing genocide). |
Used as an analogy: necessary consequences can follow from express treaty words without “implying terms” in the contractual sense. |
| JTI Polska sp. z o.o. v Jakubowski [2024] AC 621 |
Vienna Convention article 31 interpretation as a “single combined operation” (ordinary meaning, context, object/purpose). |
Applied to interpret ICSID Convention articles 53–55. |
| Maritime Delimitation in the Indian Ocean (Somalia v Kenya) [2017] ICJ Rep 3 |
Approach to treaty interpretation under Vienna Convention principles. |
Reinforced the holistic method used for ICSID Convention interpretation. |
| Fothergill v Monarch Airlines [1981] AC 251 |
Limits on using travaux préparatoires; such recourse should be rare and only in defined circumstances. |
Supported the view that where meaning is clear under article 31, travaux are only confirmatory. |
| Effort Shipping Co Ltd v Linden Management S.A. and others [1998] AC 605 |
Use of travaux préparatoires; clarity/public accessibility requirements. |
Used to describe constraints on supplementary interpretation under Vienna Convention article 32. |
| Islam v Secretary of State for the Home Department [1999] 2 AC 629 |
Importance of uniform interpretation of international instruments across contracting states’ courts. |
Supported attention to consensus in other jurisdictions on ICSID article 54(1). |
| Basfar v Wong [2022] UKSC 20, [2023] AC 33 |
Consistency in interpretation of treaty provisions across jurisdictions. |
Reinforced the relevance of international interpretative consensus. |
| Case concerning the Arrest Warrant of 11 April 2000 (Democratic Republic of the Congo v Belgium) (2002) ICJ Rep 1 |
Jurisdiction and immunity are distinct; acceptance of jurisdiction does not necessarily remove immunity. |
Distinguished: here, ICSID article 54(1) mandates recognition/enforcement “as if” a final domestic judgment, which necessarily presupposes adjudicative jurisdiction unobstructed by immunity. |
| Kingdom of Spain v Infrastructure Services Luxembourg S.à.r.l. [2023] HCA 11 |
Article 54(1) as waiver of jurisdictional immunity regarding recognition/enforcement. |
Treated as part of a broad international consensus supporting the court’s interpretation. |
| Sodexo Pass International SAS v Hungary [2021] NZHC 371 |
Article 54(1) obliges recognition/enforcement as a final judgment; immunity preserved only for execution steps. |
Cited as consistent foreign authority supporting waiver of adjudicative immunity for recognition. |
| Von Pezold v Zimbabwe WA-24NCC-322-07/2021 (27 November 2023) |
Article 54(1) prevents invoking immunity to avoid recognition/enforcement; article 55 preserves execution immunity. |
Used as additional support for international consensus. |
| Blue Ridge Investments LLC v Republic of Argentina (2012) 735 F.3d 72 |
Contracting to ICSID implies contemplation of enforcement actions in other contracting states. |
Supported the view that article 54(1) contemplates foreign-court recognition/enforcement against states. |
| Seetransport Wiking Trader Schiffarhtsgesellschaft MBH & Co, Kommanditgesellschaft v Navimpex Centrala Navala (1993) 989 F. 2d 572 |
Analogous reasoning on treaty-based contemplation of enforcement actions in other states. |
Referred to via Blue Ridge as comparative support. |
| Tethyan Copper Company Pty Limited v Islamic Republic of Pakistan BVIHC (Com) 2020/0196, 25 May 2021 |
A contrary (“outlier”) view that article 54(1) imposed no obligation before the enforcing court. |
Given little weight; the court considered it failed to account for the reciprocal obligations and consent inherent in articles 53–54. |
| Pepper (Inspector of Taxes) v Hart [1993] AC 593 |
When Hansard may be used for statutory interpretation. |
Applied to reject reliance on Parliamentary material: no ambiguity/obscurity/absurdity in the relevant statutory meaning. |
Court's Reasoning and Analysis
(1) Approach to waiver/submission under SIA 1978 section 2(2): The court held that a treaty-based waiver/submission must be a clear and unequivocal expression of consent to the exercise of jurisdiction. Whether it is “express” does not depend on using specific words like “waiver,” “submission,” or “immunity.” Meaning can be conveyed by what is necessarily inherent in the treaty’s express words and what necessarily follows from them. The relevant interpretive exercise for a treaty is governed by public international law principles (Vienna Convention articles 31–32). The court considered that the dissenting approach in Pinochet (No 3) took an unduly narrow view of what may constitute an “express” waiver, and relied instead on reasoning consistent with NML and with the later analysis in General Dynamics.
(2) Interpretation of ICSID Convention articles 53–55 (Vienna Convention article 31): The court interpreted article 54(1) in its ordinary meaning, context, and object/purpose. Article 53 provides finality and binding effect of ICSID awards subject only to ICSID remedies. Article 54(1) obliges each contracting state to recognize an award as binding and to enforce its pecuniary obligations “as if it were a final judgment” of a domestic court. Article 54(2) prescribes a procedural requirement (certified copy) but leaves machinery to each state. Article 54(3) addresses execution by reference to forum law. Article 55 expressly preserves only immunity from execution, not immunity from adjudicative jurisdiction.
The court reasoned that the scheme draws a sharp distinction between (i) recognition/enforcement (which necessarily involves an exercise of adjudicative jurisdiction culminating in domestic legal recognition “as if” a final judgment) and (ii) execution (where immunity may remain available). The express preservation of execution immunity in article 55, coupled with the absence of any preservation of adjudicative immunity in articles 53–55, supported the conclusion that contracting states accepted that adjudicative immunity would not bar recognition/enforcement.
(3) Reciprocal consent inherent in article 54(1): The court held that, by agreeing that “Each Contracting State shall” recognize and enforce awards as final judgments, each contracting state necessarily accepted that other contracting states (including the United Kingdom) would exercise adjudicative jurisdiction to recognize and enforce awards against it. That mutual obligation was inconsistent with retaining adjudicative immunity at the registration stage. This conclusion was reached from the ordinary meaning of the express terms, without “reading in” additional words or implying terms.
(4) Distinguishing “jurisdiction” from “immunity” did not assist the appellant states: While the ICJ has stated that jurisdiction and immunity are distinct, the court held that article 54(1) is directed to the end-result of the adjudicative process (treatment “as if” final judgment), which necessarily presupposes that adjudicative immunity has been displaced for recognition/enforcement.
(5) Context and purpose of the ICSID scheme: Relying in part on Micula, the court treated ICSID as a closed system built on mutual trust, in which domestic courts cannot revisit merits and in which the recognition/enforcement obligation is central to mitigating sovereign risk and encouraging investment. Preserving adjudicative immunity would be incompatible with this purpose, even if not as starkly as in Pinochet (No 3).
(6) Vienna Convention article 32 (travaux) used only confirmatorily: Because meaning was clear under article 31, travaux were unnecessary but in any event confirmed that discussion of immunity during drafting was directed to immunity from execution (leading to article 55), not to a barrier to recognition/enforcement.
(7) Comparative jurisprudence: The court noted broad international consensus (Australia, New Zealand, Malaysia, United States) interpreting article 54(1) as entailing waiver of adjudicative immunity for recognition/enforcement, treating a BVI decision as an outlier of limited weight.
(8) No decision on SIA 1978 section 9(1): Having decided issue 1 (submission via article 54(1)), the court did not hear argument or determine issue 2 (arbitration exception) and expressed no view on the Court of Appeal’s conclusions on that issue.
Holding and Implications
DISMISSED: The appeals were dismissed on issue 1. By becoming bound by ICSID Convention article 54(1), the appellant states made a clear and unequivocal prior written submission to the adjudicative jurisdiction of UK courts for the purpose of recognizing and enforcing ICSID awards, within SIA 1978 section 2(2). Accordingly, they could not oppose High Court registration of the awards under the 1966 Act on state-immunity grounds.
The Supreme Court did not determine issue 2 (SIA 1978 section 9(1)) and stated its decision should not be treated as expressing any view on the Court of Appeal’s analysis of that issue. The Court of Appeal’s remittal in State B’s case—sending the matter back for directions on State B’s reserved non-immunity defences—remains in place, and the Supreme Court expressed no view on the merits of those defences. The judgment set no new rule on immunity from execution, which the court expressly said was not in issue.