Three jurisdictions, one message: Intra-EU arbitral awards remain enforceable beyond EU borders

The dimension of domestic case law supporting the recognition and enforcement of intra-EU investment arbitration awards continues to grow. As readers may recall, with its judgments in Achmea B.V. v. The Slovak Republic I and Komstroy v. Republic of Moldova, the Court of Justice of the EU (CJEU) held that both BIT and Energy Charter Treaty (ECT) intra-EU disputes are incompatible with EU law — a finding it extended in PL Holdings S.a.r.l. v. Poland to ad hoc arbitration agreements between EU investors and EU Member States. EU Member States have since relied upon these rulings to resist intra-EU claims at every stage: by objecting to the jurisdiction of arbitral tribunals, seeking annulment of awards, and opposing their enforcement. In line with our analysis throughout this series, this line of defence — the so-called intra-EU objection — has so far proven ineffective in enforcement proceedings outside of the EU.

Since our last updates on the issue in September 2025 and December 2025, further decisions on the enforceability of intra-EU investor-state awards have come to light. These decisions from courts in Singapore, the UK, and the US confirm and strengthen the trend:

1. In Singapore, the High Court enforced the intra-EU NextEra Energy Global Holdings B.V. and NextEra Energy Spain Holdings B.V. v. Kingdom of Spain (NextEra v. Spain) award, finding that neither the state's waiver of sovereign immunity in the ICSID Convention nor the ECT's arbitration agreement was altered by EU law.
2. In the UK, the Supreme Court ruled, with respect to the intra-EU award in Infrastructure Services Luxembourg S.à.r.l. and Energia Termosolar B.V. v. Kingdom of Spain (Antin v. Spain), that Spain had waived its sovereign immunities from jurisdiction with respect to ICSID awards.
3. In the US, the US District Court for the District of Columbia granted summary judgment in a petition to enforce the intra-EU ECT award in MOL Hungarian Oil and Gas Company Plc v. Republic of Croatia I (MOL v. Croatia I).

We address these developments below, which once again highlight the importance of pursuing a global strategy when seeking enforcement of these awards.

1. Singapore court rules that EU law cannot override ICSID Convention obligations or the ECT’s arbitration clause

On 24 February 2026, the Singapore High Court dismissed Spain’s application to set aside the registration order for the ICSID award in NextEra v. Spain, an arbitration under the ECT. The High Court ruled that Spain did not have state immunity in the proceedings on two independent grounds: first, by entering into the ICSID Convention, Spain had submitted to the jurisdiction of the Singapore courts for registration and enforcement proceedings; and second, Spain had agreed in writing to submit the dispute to arbitration pursuant to Article 26 ECT, thereby triggering the arbitration exception to state immunity under Singapore law.

The court followed the reasoning of several other jurisdictions affirming that national courts have no ability to second-guess the binding nature of ICSID awards owing to ICSID's nature as a "self-contained" system. It confirmed that a party dissatisfied with an ICSID award may apply for annulment to an annulment committee, but if it fails to annul the award, it cannot challenge the binding nature of the award by disputing the jurisdiction of the ICSID tribunal before a national court. The court further concluded that a registering or enforcing court need not satisfy itself as to the ICSID tribunal’s jurisdiction in order to find that ICSID Contracting Parties have, by entering into the ICSID Convention, submitted to jurisdiction in relation to recognition and enforcement proceedings. 

The court also dismissed the intra-EU argument that EU law primacy rendered the ECT’s arbitration clause inapplicable to intra-EU disputes. It emphasized the non-applicability of EU law primacy on the international plane and the absence of any disconnection clause for intra-EU disputes. The High Court concluded that setting aside the registration order would not be in the interests of justice, noting that “Spain's predicament is the result of the treaties that it entered into.”

Notably, the High Court decision in NextEra v Spain extends to the enforcement arena the reasoning in a landmark judgment issued by the Singapore International Commercial Court (SICC) on 9 January 2026. In DNZ v DOA, the SICC rejected in an anonymized judgment the state’s intra-EU objection as a basis to set aside an intra-EU ECT award issued in an UNCITRAL arbitration with its seat in Singapore. The SICC’s analyses were mirrored in many respects in the NextEra judgment. The SICC also found that the declarations signed by a majority of EU member states in 2019 and 2024, affirming the incompatibility of intra-EU arbitration with EU law, did not amount to a modification of the ECT. 

These two judgments mark the first time Singapore’s courts have ruled on the intra-EU jurisdictional objection.

2. UK Supreme Court confirms sovereign immunity waiver under the ICSID Convention

In a landmark judgment handed down on 4 March 2026 with respect to the Antin v. Spain award and the award in Border Timbers Limited, Timber Products International (Private) Limited, and Hangani Development Co. (Private) Limited v. Republic of Zimbabwe (Border Timbers v. Zimbabwe), the UK Supreme Court confirmed that respondent states cannot rely on sovereign immunity to resist the recognition and enforcement of ICSID awards in the UK. 

The holders of the intra-EU Antin v. Spain award have pursued enforcement of the award across multiple jurisdictions, including the UK, the US, and Australia. The case was joined at the level of the Court of Appeal with the Border Timbers v Zimbabwe enforcement proceedings to resolve a split between lower court judges over the states’ reliance on sovereign immunities from jurisdiction under the 1978 State Immunity Act (SIA). The Supreme Court endorsed the Court of Appeal's analysis entirely, holding that Article 54(1) of the ICSID Convention — which obliges all contracting states to recognize ICSID awards as binding — waives sovereign immunity under Section 2(2) of the SIA.

The Supreme Court held that states cannot simultaneously undertake to recognize the binding character of awards and to enforce them as final judgments of their own courts, while shielding themselves with sovereign immunity from jurisdiction. Notably, the court clarified that an “express” waiver of immunity by treaty need not involve explicit words such as “waiver” or “submission”. Rather, what matters is that there is a clear and unequivocal expression of the state’s consent to the exercise of jurisdiction, having regard to the normal exercise of treaty interpretation. The test is whether the words used “necessarily lead to the conclusion that the state has submitted to the jurisdiction” (in turn, affirming the approach taken by the House of Lords in Pinochet (No 3), where the Convention Against Torture was held to contain an express waiver of immunity).

On that test, the Supreme Court held that the words used in Article 54(1) of the ICSID Convention “could not be a clearer submission to the jurisdiction”. 

That conclusion was held to be reinforced by:

• the treaty context, given the support for this interpretation in Articles 27 and 69 of the ICISD Convention;
• the ICSID Convention's object and purpose, which was to provide for “mandatory recognition and enforcement in respect of all parties, investors and states alike”;
• the preparatory works of the ICSID Convention; and
• the broad international consensus among courts in Australia, New Zealand, Malaysia, and the US. (And notably, the Court expressed some disapproval of the now well-known outlier decision in TCC v Pakistan in the High Court of the BVI, where a claim to state immunity from jurisdiction under Article 54(1) of the ICSID Convention was upheld.)

3. US District Court holds that intra-EU objection cannot override ICSID obligations

On 5 March 2026, the US District Court for the District of Columbia became the latest US court to enforce an intra-EU award when it granted summary judgment in favor of MOL Hungarian Oil and Gas in its petition to confirm the ICSID award in MOL v. Croatia I. The court found that Croatia could not evade enforcement based on the purported invalidity of its consent to arbitrate intra-EU disputes under the ECT.

The court reiterated that US courts are courts of enforcement for ICSID awards, not review, and that ICSID awards are entitled to full faith and credit just like US state court judgments. The court therefore held that its obligation to enforce pecuniary obligations from ICSID awards did not permit revisiting substantive findings, including the tribunal’s jurisdictional determination. Accordingly, the court rejected Croatia’s argument that the award did not give rise to enforceable pecuniary obligations because it was invalidly rendered.  

The court also dismissed Croatia’s argument on the foreign sovereign compulsion doctrine, under which a party may be excused from liability when its conduct was compelled by a clear, mandatory foreign law or governmental order, creating a genuine conflict where compliance with one legal system necessarily entails a breach of another. EU states have invoked this doctrine to argue that EU law prevents them from complying with intra-EU arbitral awards. 

This ruling follows the Court of Appeals for the DC Circuit’s landmark decision in NextEra v. Spain, which held that the ECT constituted an arbitration agreement binding on EU member states even in the intra-EU context, and which we analyzed here. That decision is now pending review before the US Supreme Court, a development that could further shape the enforcement landscape in the US. This pivotal ruling is expected in the coming months.

Takeaways

As favorable enforcement decisions continue to accumulate across jurisdictions, the strategy of maintaining a holistic, multi-forum strategy when seeking to monetize intra-EU awards continues to gain strength. The three decisions discussed above reinforce the key takeaway for practitioners and parties involved in intra-EU arbitration: it remains viable to recognize and enforce intra-EU arbitral awards outside of the EU.