1 The present appeal in CA/CA 11/2026 (“CA 11”) concerns the registration and enforcement of an arbitral award (“Award”) rendered by the International Centre for Settlement of Investment Disputes (“ICSID”). The Award was made in favour of the respondents, whom we refer to as the “Dutch Investors”, and against the appellant, the Kingdom of Spain (“Spain”).

2 The Dutch Investors subsequently obtained an order registering the Award in Singapore (“Registration Order”). Spain applied to set aside the Registration Order, principally on the ground that it was entitled to state immunity under s 3 of the State Immunity Act 1979 (2020 Rev Ed) (“SIA”). This application was dismissed by a Judge of the General Division of the High Court (“Judge”): see NextEra Energy Global Holdings BV v Kingdom of Spain [2026] SGHC 43 (“Judgment”). The Judge found that Spain could not rely on state immunity under s 3 of the SIA to set aside the Registration Order because the exceptions to state immunity in ss 4 and 11 of the SIA applied. The Judge also declined to set aside the Registration Order under O 3 r 2(8) of the Rules of Court 2021 (“ROC 2021”) in the interests of justice. Before us, Spain contends that the Judge erred in each of these respects, and we address each ground of appeal in turn.

3 Having reserved judgment after hearing parties’ submissions, we now provide our decision along with our reasons.

4 The underlying dispute in the arbitration (“Dispute”) arose out of investments made by the Dutch Investors in Spain. In May 2014, the Dutch Investors commenced ICSID arbitration (ICSID Case No. ARB/14/11) against Spain pursuant to the Energy Charter Treaty (17 December 1994), 2080 UNTS 95 (entered into force 16 April 1998) (“ECT”), to which Spain and the Netherlands were both contracting parties.

5 The ICSID arbitration resulted in the Award rendered against Spain on 31 May 2019 by the arbitral tribunal (“Tribunal”). In accordance with the ICSID framework, Spain then applied to annul the Award before an ad hoc annulment committee (“annulment committee”) but was unsuccessful. The annulment committee’s decision (“Decision on Annulment”) was delivered on 18 March 2022.

6 Before the Tribunal, Spain objected to its jurisdiction, arguing, amongst other things, that the dispute resolution mechanism set out in Art 26 of the ECT did not apply to controversies arising between an investor of a member state of the European Union (“EU Member State”) and another EU Member State (“intra-EU disputes”). Spain reiterated this argument before the annulment committee. Both the Tribunal and the annulment committee rejected that argument.

7 In December 2023, the Dutch Investors applied in HC/OA 1283/2023 (“OA 1283”) to register the Award and the Decision on Annulment in the General Division of the High Court. The Registration Order was granted in January 2024, with the court ordering that the Award and the Decision on Annulment be registered as if they were judgments of the General Division of the High Court (Judgment at [8]).

8 In May 2025, Spain applied by way of HC/SUM 1371/2025 (“SUM 1371”) to set aside the Registration Order (Judgment at [9]).

9 The key issue before the court below was whether the exceptions to state immunity in ss 4 and 11 of the SIA applied. Sections 3, 4 and 11 of the SIA state as follows:

10 Spain argued that it was immune from the jurisdiction of the Singapore court under s 3 of the SIA in respect of proceedings for the registration and enforcement of the Award, and that the exceptions to state immunity in s 4 of the SIA (“Submission Exception”) and s 11 of the SIA (“Arbitration Exception”) did not apply.

(a) On the Submission Exception, Spain argued that its accession to the Convention on the Settlement of Investment Disputes between States and Nationals of Other States (18 March 1965), 575 UNTS 159 (entered into force 14 October 1966) (“ICSID Convention”) did not amount to submission to the jurisdiction of the Singapore courts under s 4(1) of the SIA.

(b) On the Arbitration Exception, Spain argued that there was no valid agreement to arbitrate the Dispute because no valid agreement to arbitrate intra-EU disputes could exist as a matter of European Union (“EU”) law (“Intra-EU Objection”). Spain further contended that, in any event, it had not in fact offered to arbitrate the Dispute with the Dutch Investors.

(c) Spain further argued that the Submission Exception was contingent upon the Arbitration Exception also applying (“Codependent Argument”). In short, Spain contended that these were not self-standing exceptions such that the successful invocation of the former would in itself suffice to displace Spain’s immunity from registration and enforcement proceedings.

11 In the alternative, Spain argued that the Registration Order should be set aside in the interests of justice.

12 Turning to the Dutch Investors’ position, they argued that the Submission Exception applied as Spain had submitted to the jurisdiction of the Singapore courts by acceding to the ICSID Convention.

13 On the Arbitration Exception, the Dutch Investors argued, amongst other things, that pursuant to Art 26 of the ECT, Spain had agreed to arbitrate the Dispute with the Dutch Investors, and this resulted in the Award. They further contended that, under the ICSID Convention, an enforcement court is not permitted to reopen the tribunal’s finding that a valid arbitration agreement existed.

14 The Dutch Investors also argued that it would not be in the interests of justice to set aside the Registration Order.

15 The Judge dismissed Spain’s application to set aside the Registration Order.

16 The Judge found that the Submission Exception to state immunity in s 4 of the SIA applied. The Judge noted that the weight of authority on the Submission Exception was against Spain, and that courts of various jurisdictions have held that accession to the ICSID Convention constitutes a submission to jurisdiction, in respect of applications to recognise or enforce an ICSID award (Judgment at [19]). The Judge held that by entering into the ICSID Convention, Spain had submitted to the jurisdiction of the courts of other contracting parties to the ICSID Convention (“Contracting States”), for the purpose of ICSID recognition and enforcement proceedings. Further, it was not necessary for the registering and enforcing court first to find that the Arbitration Exception applied before it could find that the Submission Exception applied (Judgment at [70]–[74]).

17 Although the Submission Exception was sufficient to dispose of the issue of state immunity, the Judge also considered the Arbitration Exception and found that it applied as well. He held that pursuant to Art 26 of the ECT, Spain had agreed in writing to submit the Dispute with the Dutch Investors to arbitration, and that the Intra-EU Objection did not provide a valid basis for Spain to deny the existence of that agreement (Judgment at [79]–[84], [103]–[123]).

18 Finally, the Judge declined to set aside the Registration Order in the interests of justice, finding that to accede to Spain’s request would be to act contrary to the ICSID Convention and the Arbitration (International Investment Disputes) Act 1968 (2020 Rev Ed) (“AIIDA”), which the court could not do (Judgment at [124]–[134]).

19 Spain’s case on appeal is that the Submission Exception and Arbitration Exception are not applicable. In this regard, Spain first repeats the Codependent Argument (see above at [10(c)]) and contends that neither the Submission Exception nor Arbitration Exception may apply unless it can be shown that there was a valid arbitration agreement giving rise to the arbitration. The essence of this argument is that the Judge erred in finding that Spain had submitted to the jurisdiction of the courts of other Contracting States simply by virtue of its accession to the ICSID Convention. On Spain’s case, a State’s accession to the ICSID Convention does not itself amount to a submission to the jurisdiction of a foreign enforcement court. Instead, some other act or instrument of consent is required to bring the ICSID Convention into play. In the present case, the only instrument capable of doing so was the ECT. However, on a true construction of the ECT, Spain submits that it never offered to arbitrate the Dispute with the Dutch Investors under the ICSID Convention. It follows, therefore, that in the absence of a valid agreement to arbitrate, neither the Arbitration Exception nor, consequently, the Submission Exception can be made out.

20 At the hearing before us, counsel for Spain, Mr Siraj Omar SC (“Mr Omar”) advanced two further arguments in support of the contention that the Judge erred in finding that the Submission Exception applied. First, the Judge’s approach to s 4 of the SIA would result in a blanket lifting of immunity for all ICSID awards in registration and enforcement proceedings, and this was not what Parliament intended when enacting the SIA. Second, there is no statement in Art 54 of the ICSID Convention which provides for a deemed waiver of state immunity.

21 In the event that Spain’s arguments on state immunity fail, Spain argues that the Registration Order should nonetheless be set aside as it is in the interests of justice to do so.

22 Lastly, Spain also argues that the Judge erred in his decision on the costs of the proceedings below in SUM 1371.

23 We note for completeness that Spain raised two further arguments in its written submissions though not in the course of the oral arguments:

(a) First, Spain argued that it is not precluded from invoking state immunity under the SIA as a basis for opposing registration under the AIIDA and the Arbitration (International Investment Disputes) Rules (2002 Rev Ed). The Dutch Investors take the position that the court need not decide this issue, because they are content to proceed on the basis that state immunity may in principle apply, save that they contend that at least one of the exceptions to such immunity that they have raised does avail. The Dutch Investors also accept that the burden of proving that one of the exceptions applies is on them. We agree that it is unnecessary to resolve this point, and our analysis accordingly focuses on whether the Submission Exception and the Arbitration Exception are made out on the facts of the present case.

(b) Second, Spain contended that it is not precluded by transnational issue estoppel from raising the Intra-EU Objection before this court. Though the Judge offered some observations on this issue, he ultimately found it unnecessary to decide this point. We are of the same view, and say nothing further on it.

24 On the Submission Exception, the Dutch Investors contend that the Judge was correct in finding that it applied and rejecting the Codependent Argument. Spain had agreed to Art 54(1) of the ICSID Convention, and by doing so had submitted to the jurisdiction of the courts of other Contracting States for the purposes of recognition and enforcement proceedings arising from an award made thereunder.

25 On the Arbitration Exception, the Dutch Investors contend that it too applies. By agreeing to Art 26 of the ECT, Spain had consented to refer disputes arising under the ECT to arbitration under the ICSID Convention, and the Arbitration Exception is accordingly satisfied on the facts of the present case.

26 The Dutch Investors further submit that the Judge was correct to find that the interests of justice do not require the Registration Order to be set aside, and that his costs order in respect of the proceedings below in SUM 1371 should not be disturbed.

27 The following issues arise for our consideration:

(a) First, whether the Submission Exception in s 4 of the SIA applies.

(b) Second, whether the Arbitration Exception in s 11 of the SIA applies.

(c) Third, whether it is in the interests of justice to set aside the registration of the Award.

(d) Fourth, whether the Judge erred in his decision on the costs of SUM 1371.

28 We begin our analysis with the Submission Exception under s 4 of the SIA. The question, whether Spain’s entry into the ICSID Convention amounted to submission to the jurisdiction of the Singapore courts under s 4(1) of the SIA in respect of proceedings to register or enforce ICSID awards, turns on the proper interpretation of Art 54 of the ICSID Convention.

29 Articles 53 to 55 of the ICSID Convention state as follows:

30 We agree with the Judge that by entering into the ICSID Convention, Spain submitted to the jurisdiction of the courts of other Contracting States in respect of proceedings to register or enforce ICSID awards. The plain wording of Art 54(1) of the ICSID Convention binds each Contracting State to recognise and enforce awards rendered pursuant to the ICSID Convention. In our judgment, this obligation is necessarily reciprocal in character. A State that undertakes to recognise and enforce ICSID awards rendered against others must, by the same token, accept that it, in turn, will be subject to the jurisdiction of the courts of other Contracting States when it is itself the party against whom recognition and enforcement of an ICSID award is sought.

31 This conclusion follows, in our judgment, from the logic and structure of the ICSID Convention itself. If each Contracting State were entitled to enforce ICSID awards against others while simultaneously asserting state immunity when an award is rendered against it, the result would be two irreconcilable regimes operating in tandem. Such an interpretation cannot be correct and is plainly inconsistent with the purpose that Art 54 was designed to serve.

32 In that light, we turn to the application of s 4 of the SIA in the present context. Section 4(2) of the SIA provides that a State may submit to the jurisdiction of the Singapore courts by a “prior written agreement”, and s 2(2)(a) of the SIA makes clear that references to an agreement in s 4(2) include references to “a treaty, convention or other international agreement”. Spain’s accession to the ICSID Convention – and in particular its agreement to the obligations set out in Art 54 – constitutes precisely such a prior written agreement. It follows that Spain has submitted to the jurisdiction of the Singapore courts in respect of proceedings to register or enforce ICSID awards, and the Submission Exception under s 4 of the SIA is accordingly made out.

33 Before us, Mr Omar submitted that Art 54 of the ICSID Convention contains no express language providing for a waiver of state immunity, and that the Judge was therefore wrong to find that the Submission Exception applied. We do not accept this argument. While we accept that Art 54 does not employ the language of waiver, in our judgment, its effect is nonetheless to bring about precisely that result for the reasons we have just canvassed. This view is also consistent with the approach taken by courts in other jurisdictions that have considered the same question.

34 In Kingdom of Spain v Infrastructure Services Luxembourg S.à.r.l. [2023] HCA 11 (“Spain HCA”), counsel for the appellant raised a similar argument, contending that Art 54(1) said nothing “expressly” about a waiver of immunity (at [68]). The High Court of Australia rejected that argument and concluded that the express terms of Art 54(1) of the ICSID Convention involved a waiver of immunity from jurisdiction in relation to recognition and enforcement proceedings (at [8] and [69]–[75]). It arrived at this conclusion after having regard to the principle of international law that where it is contended that immunity has been waived by entering into a treaty, such waiver must be “express” (at [19]–[26]).

35 A similar conclusion was reached by the Supreme Court of the United Kingdom (“UKSC”) in The Kingdom of Spain v Infrastructure Services Luxembourg S.À.R.L. [2026] UKSC 9 (“Spain UKSC”). After examining the ordinary meaning of Arts 53 to 55 of the ICSID Convention, the UKSC concluded that on a correct interpretation of Art 54(1), that provision amounted to a waiver of any right of a Contracting State to assert state immunity (at [88]–[89]). This conclusion was reinforced upon an examination of the treaty context and the object and purpose of the ICSID Convention (Spain UKSC at [97]–[117]). In the result, the UKSC was satisfied that Art 54(1) was a clear and unequivocal submission to the adjudicative jurisdiction of the English courts for the purposes of recognising and enforcing the arbitral awards in question (Spain UKSC at [118]). The UKSC also observed that a similar position had been adopted by various jurisdictions, including New Zealand, Malaysia, and the United States (Spain UKSC at [135]–[140]). We would add that Mr Omar quite properly acknowledged before us that the weight of authority on this issue was against Spain.

36 We agree with the reasoning in both Spain HCA and Spain UKSC. There is also, in our judgment, considerable value in interpreting Art 54 of the ICSID Convention in a manner that is consistent with the approach taken by the courts of other Contracting States. Multilateral treaties such as the ICSID Convention are entered into on the basis of mutual and reciprocal obligations, and it would be incongruous for the courts of one Contracting State to interpret those obligations in a manner that the courts of other Contracting States would find surprising and incongruent with the general understanding of the provisions of such a treaty. That is an even weightier consideration in the present context where adopting an interpretation of Art 54 that is contrary to the way in which the courts of other Contracting States have approached this would render the ICSID Convention’s enforcement mechanism largely dysfunctional and defeat a key purpose of entering into the ICSID Convention in the first place. On the other hand, a consistent interpretation of Art 54, as we adopt in this case, reduces the scope for forum shopping, facilitates the enforcement of awards across Contracting States, strengthens confidence in the arbitral process itself, and upholds the key purposes of the ICSID Convention.

37 We would add a further point. As this court observed in The Republic of India v Deutsche Telekom AG [2024] 1 SLR 56 (“Deutsche Telekom”) at [122], the Singapore courts are duty-bound to interpret domestic legislation and develop the common law, so far as it is permissible, in a manner that advances Singapore’s international obligations. The interpretation we have adopted – that Spain’s accession to the ICSID Convention constitutes submission to the jurisdiction of the Singapore courts within the meaning of s 4 of the SIA – is, in our view, not only the interpretation that best accords with the text and purpose of Art 54, but also the interpretation that gives proper effect to Singapore’s obligations under the ICSID Convention.

38 We next address Mr Omar’s argument that this interpretation of s 4 of the SIA would result in the blanket lifting of state immunity for all ICSID awards in registration and enforcement proceedings. With respect, we think this mischaracterises the issue. To the extent it is said that entry into the ICSID Convention will generally give rise to an obligation to enforce ICSID awards rendered against other Contracting States, and in turn will amount to a waiver of any immunity which that State might otherwise have against enforcement in the courts of another Contracting State in respect of an award made against it, this is simply the effect of Arts 53 to 55 of the ICSID Convention.

39 The issue of how the courts would deal with an award infected by fraud was also raised at the hearing before us. In this regard, we have two observations. First, it is not necessary for us to resolve that question here, because it does not arise on the facts before us. And, second, we would observe that the court retains a residual discretion under O 3 r 2(8)(d) of the ROC 2021 to revoke any judgment or order obtained or to set aside anything which was done by fraud or misrepresentation, if it is in the interests of justice to do so. How and whether that applies to proceedings to enforce an award under the ICSID Convention is something we need not and do not decide here.

40 In the circumstances, we are satisfied that the Judge did not err in finding that the Submission Exception in s 4 of the SIA applies.

41 We turn next to the Codependent Argument. The upshot of Spain’s argument is that the Submission Exception cannot apply unless the Arbitration Exception is also made out. We do not accept this argument. Sections 4 to 13 of the SIA set out different and separate exceptions to state immunity under s 3 of the SIA. Each exception stands alone and is not dependent on any other. This is clear from the plain wording of the SIA – none of the exceptions to immunity expressly refer to any of the other exceptions. Accepting Spain’s argument would thus amount to an impermissible rewriting of s 4 of the SIA.

42 As our analysis at [28]–[32] above makes clear, our conclusion that the Submission Exception applies rests on the obligations that Spain undertook upon its entry into the ICSID Convention. Spain’s submission to the jurisdiction of the Singapore courts is therefore premised on Spain’s entry into the ICSID Convention and where an award is rendered pursuant to the ICSID Convention, the award creditor’s right to enforce it as a judgment is not contingent upon the award creditor separately proving to the satisfaction of the enforcement court, the existence or validity of the underlying agreement to arbitrate which gave rise to the award in question.

43 Since we are satisfied that the Submission Exception is made out, it follows that Spain cannot invoke state immunity under s 3 of the SIA. Spain therefore stands in the same position as any party seeking to resist the registration or enforcement of an ICSID award and must rely on any available grounds outside the SIA – which is concerned only with the issue of immunity – to set aside the Registration Order. It is accordingly strictly unnecessary for us to consider whether the Arbitration Exception under s 11 of the SIA is also satisfied. We nonetheless make some brief observations on this issue as it was argued before us.

44 The nub of Spain’s argument in relation to the Arbitration Exception in s 11 of the SIA is its contention that it had not agreed to refer disputes between itself and investors of other EU Member States to arbitration. In support of this, it contends that under EU law, there can be no valid arbitration agreement between an EU Member State and a national of another EU Member State.

45 The question whether Spain had agreed or could agree to arbitrate the Dispute with the Dutch Investors may well be a legitimate one. However, there remains an issue as to whether it is a question to be decided by this court.

46 The ICSID regime is intended to operate as a self-contained regime. This is evident from the provisions of the ICSID Convention:

(a) We begin with Art 26 of the ICSID Convention, which provides that the consent of the parties to arbitration under the ICSID Convention shall, unless otherwise stated, be deemed consent to such arbitration to the exclusion of any other remedy.

(b) Article 41 provides that an ICSID tribunal shall be the judge of its own competence, and that any objection by a party that the dispute is not within the jurisdiction of the ICSID, or for other reasons is not within the competence of the ICSID tribunal, shall be considered by the ICSID tribunal, whether as a preliminary question or together with the merits of the dispute. And there is no provision within the ICSID Convention for the parties to have recourse to any remedy other than to seek an appropriate ruling from the arbitration tribunal in respect of that tribunal’s jurisdiction.

(c) Article 50 provides that if any dispute arises between the parties as to the meaning or scope of an award, either party may apply for the interpretation of the award by the ICSID tribunal.

(d) Article 51 provides that the parties may request the ICSID tribunal to revise an award on the ground of some material fact that was previously unknown to the ICSID tribunal and the applicant, provided that the applicant’s ignorance of that fact was not due to negligence, and that the application is made within 90 days of the discovery and within three years after the date on which the award was rendered.

(e) Article 52 provides that the parties may apply for the annulment of an award on the following grounds:

Any such annulment application is to be heard by an ad hoc committee appointed by the ICSID chairman. If the award is annulled the dispute shall, at the request of either party, be submitted to a new ICSID tribunal constituted in accordance with the relevant articles of the ICSID Convention.

(f) Article 53 provides, in no uncertain terms, that the award of the ICSID tribunal “shall not be subject to any appeal or to any other remedy except those provided for in [the ICSID Convention]”. Article 54 also provides that each Contracting State shall recognise an award rendered pursuant to the ICSID Convention as binding as if it were a final judgment of a court in that State. The ICSID Convention differs in this regard from other regimes such as the Convention on the Recognition and Enforcement of Foreign Arbitral Awards (10 June 1958), 330 UNTS 38 (entered into force 7 June 1959), which is the New York Convention: see Judgment at [48], citing Deutsche Telekom at [123].

47 The foregoing provisions reflect a set of deliberate choices made in creating a self-contained scheme for producing binding awards. Article 41 of the ICSID Convention envisions that an ICSID tribunal is empowered and competent to decide matters of its own jurisdiction, which would include the issue of whether there was a valid agreement to refer the dispute to arbitration under the ICSID regime. The ICSID tribunal’s decision on its competence is then subject only to the ICSID regime’s internal review or annulment process set out in Arts 50 to 52. And by Arts 53 and 54, the parties to the dispute have no recourse to any other remedy and Contracting States are obliged to recognise such awards as binding as if they were final judgments of a court in that State. There is thus no avenue under which a domestic court may revisit the ICSID tribunal’s finding as to its own competence.

48 In recognition of this, the AIIDA, which is the domestic legislation implementing and giving effect to Singapore’s obligations under the ICSID Convention, does not provide any other avenue for reconsideration of the merits of the ICSID tribunal’s decisions. Section 4(1) of the AIIDA provides as follows:

There is nothing in the text of s 4(1) which creates an avenue for reconsideration of the merits of the award. Mr Omar candidly acknowledged before us that there is no provision in the AIIDA which grants the Singapore court the power to refuse enforcement of an award rendered pursuant to the ICSID Convention, in particular, on the ground that there is no valid arbitration agreement. As for the reference to “proof of any matters that may be prescribed”, this is directed at procedural requirements which may be prescribed pursuant to s 6 of the AIIDA, such as requirements that the applicant give prior notice of its intention to register to other parties, proof of such notice, and proof of the award itself. In our view, nothing in s 4(1) of the AIIDA opens the door to any substantive review of an ICSID award.

49 In our judgment, Spain’s argument amounts to a suggestion that the court may, in effect, import into the AIIDA a provision akin to s 31(2)(b) of the International Arbitration Act 1994 (2020 Rev Ed) which allows the Singapore court to refuse enforcement of an award where it is satisfied that there is no valid arbitration agreement. We disagree. There are, in our view, at least three difficulties with this suggestion:

(a) First, we have no basis for doing so.

(b) Second, as we have explained above, the ICSID Convention is intended to be self-contained. We reiterate our observation at [37] above that the Singapore courts are obliged to interpret domestic legislation and develop the common law, as far as permissible, in a manner that advances Singapore’s international obligations. It would be inconsistent with the ICSID Convention’s self-contained nature for us to contemplate making an ICSID award subject to additional scrutiny by a Singapore court, when this is not in the AIIDA, and further, when it defeats a key feature of the ICSID regime.

(c) Third, importing a provision which allows a Singapore court to refuse enforcement of an ICSID award on the grounds that there was no valid arbitration agreement would also run contrary to Art 41 of the ICSID Convention, which contemplates that the competence of the ICSID tribunal is a matter for the ICSID tribunal itself to decide, rather than the court of a Contracting State, and Art 53, which provides that such an award shall be subject to no other remedy except those provided for in the ICSID Convention.

50 These views are consistent with the position adopted by various other jurisdictions. We highlight, in particular, Kingdom of Spain v Infrastructure Services Luxembourg S.à.r.l. [2021] FCAFC 3 (at [114]), where the Full Court of the Federal Court of Australia took the view that the jurisdiction of the ICSID tribunal was not a matter that the Australian courts could consider, and that the sole issue for the competent court under Art 54(2) of the ICSID Convention is whether the party seeking recognition of the award has provided a certified copy of it.

51 And in the United Kingdom, the UKSC in Micula v Romania [2020] 2 All ER 637 observed as follows (at [68]):

52 In this regard, we reiterate our observations (at [36]) as to the desirability of interpreting the provisions of a treaty like the ICSID Convention in a manner that is consistent with the approach taken by the courts of other Contracting States, and that advances its purpose.

53 Spain has cited the decision in Border Timbers Ltd v Republic of Zimbabwe [2024] 1 WLR 3417 (“Border Timbers (EWHC)”) for the proposition that a domestic court must be independently satisfied that there was a valid agreement to arbitrate, notwithstanding the seemingly sealed and self-contained nature of the regime established by the ICSID Convention. In Border Timbers (EWHC), the court, when interpreting s 9 of the State Immunity Act 1978 (c 33) (UK) (“English SIA”) (which is in pari materia with s 11 of the SIA), considered that s 9 was a provision of general application that must apply equally to ICSID and non-ICSID awards. The High Court of England and Wales (“EWHC”) considered that the sealed nature of the ICSID regime had no bearing on the EWHC’s obligation to consider whether there was a valid arbitration agreement that would bring the matter within the ambit of s 9 of the English SIA. In this regard, the court noted that the ICSID process would not be engaged at all if no such agreement existed (at [88]–[90]). However, these observations were not, strictly speaking, part of the decision of the court, which turned on the EWHC’s conclusion that the question of state immunity did not arise in respect of an application to register an ICSID award (at [106]–[110]).

54 The English Court of Appeal in Infrastructure Services Luxembourg S.À.R.L. v Kingdom of Spain [2025] 2 All ER 693 (at [105]) made similar observations, although again, not as part of its decision. The court was not prepared to accept that a State would be precluded from disputing the existence of a valid arbitration agreement just because the award had been rendered under the ICSID Convention. The court preferred instead to read s 9 of the English SIA as imposing on the court a duty to satisfy itself that the State in question had in fact agreed in writing to submit the dispute to arbitration (at [104]–[106]). When the matter came before the UKSC in Spain UKSC, the court did not address or comment on these observations.

55 We agree that s 11 of the SIA should apply equally to ICSID and non-ICSID awards. However, the difference between ICSID and non-ICSID awards, in our view, may lie in whether the enforcement court may consider the applicability of the Arbitration Exception independently of, and altogether disregarding, the findings of the ICSID tribunal and of an ICSID annulment committee on those very issues. In our present view, where a Contracting State is asked to enforce an ICSID award, the State against which enforcement is sought must, by virtue of its agreement to the ICSID Convention, be taken to have submitted to the jurisdiction of the courts of that Contracting State by the operation of Art 54. The Submission Exception in s 4 of the SIA will therefore be engaged. It follows that, in the case of an ICSID award, there will ordinarily be no need to consider the Arbitration Exception in s 11 of the SIA separately. But quite apart from that, there is the additional consideration that by entering into the ICSID Convention, the State against which enforcement is sought will also have agreed that its rights to contest the jurisdiction of the tribunal are those set out in the ICSID Convention. In these circumstances, it is not clear to us how such a State may nonetheless contend that it may seek recourse against the award being enforced by a ruling from the enforcement court that contradicts the findings of the ICSID tribunal or annulment committee. In any case, this was not a live issue before us and it is not necessary for us to come to a concluded view on this given that we have found that there was a submission to the jurisdiction of the court pursuant to s 4 of the SIA.

56 Spain also contends in its written submissions that, in the event that its arguments on state immunity fail, the Registration Order should nonetheless be set aside on the ground that it is in the interests of justice to do so. Specifically, Spain invokes O 3 r 2(8)(a) of the ROC 2021 as the Registration Order was obtained on a “without notice” basis.

57 The thrust of Spain’s case in this regard is that it should not be made to act in a manner contrary to its own laws and EU law. As to this, we highlight this court’s observations in AnAn Group (Singapore) Pte Ltd v VTB Bank (Public Joint Stock Company) [2022] 1 SLR 771 that the inherent powers of the court to prevent injustice or an abuse of the court process are only exercised in exceptional circumstances and the essential touchstone is one of need (at [95]).

58 In our view, no exceptional circumstances arise on the facts of this case. We agree with the Judge that there is nothing unjust in holding Spain to the consequences flowing from the treaty obligations that it had voluntarily entered into (Judgment at [130]–[131]). Rather, to accede to Spain’s request and set aside the Registration Order would result in prejudice to the Dutch Investors, who are entitled to have the Award registered in Singapore pursuant to s 4 of the AIIDA, and thereby put Singapore in breach of its obligations under Art 54 of the ICSID Convention. Such a result cannot be in the interests of justice.

59 Accordingly, we find that there are no grounds for the exercise of the court’s inherent power to set aside the Registration Order in the interests of justice.

60 We turn lastly to deal with Spain’s appeal against the Judge’s decision on costs in SUM 1371. The Judge awarded the Dutch Investors $80,000 in costs for SUM 1371. Spain argues that the Judge should have awarded costs of $44,000 instead. Spain submits that the Judge erred in having regard to the range prescribed for contested originating applications of $12,000–$30,000 per day under Appendix G of the Supreme Court Practice Directions 2021 (“SCPD 2021”), and that he ought instead to have applied the range prescribed for complex or lengthy applications fixed for special hearing, which is a range of $9,000–$22,000.

61 We deal with this briefly. In our judgment, Spain’s appeal against the Judge’s costs order in SUM 1371 fails on two grounds.

62 First, Spain’s appeal in this respect is procedurally defective. Spain’s Notice of Appeal for CA 11 was filed on 9 April 2026, and the Judge’s costs decision was issued subsequently on 6 May 2026. As we explained in The “Luna” [2021] 2 SLR 1054 at [104(b)], where a costs decision is delivered after a notice of appeal has already been filed against the substantive decision, an appellant who seeks a different costs order regardless of the outcome of the substantive appeal must seek leave to file an additional notice of appeal against the costs decision. Spain’s appeal against the costs order is plainly of this character, since Spain contends that the Judge should have awarded costs of $44,000 for SUM 1371 irrespective of the outcome of the present appeal. Spain did not seek such leave, and its appeal on this issue is procedurally defective.

63 Second, and in any event, we see no basis to interfere with the Judge’s costs order. Contrary to Spain’s submission, the Judge did not rely solely on the range for contested originating applications in Appendix G of the SCPD 2021. Instead, in coming to his decision to award $80,000 for the costs of SUM 1371, the Judge expressly had regard to the range prescribed for both arbitration originating applications and “complex or lengthy application(s) fixed for special hearing (duration of 3hrs)” in Appendix G of the SCPD 2021. The Judge also took into account the complexity and novelty of the issues, the duration of the hearing, and the work done by the parties. The resulting award of $80,000 plus disbursements was, in our judgment, well within the range of a reasonable exercise of the Judge’s discretion, and we decline to disturb it.

64 We therefore dismiss the appeal. We fix the costs of the appeal at $50,000 all in, in favour of the Dutch Investors.