The right to strike

On May 21, 2026, the International Court of Justice (ICJ, or the Court) issued an advisory opinion concluding, by ten votes to four, that the right to strike of workers and their organizations is protected under the Freedom of Association and Protection of the Right to Organise Convention, 1948 (ILO Convention Nº. 87) (International Court of Justice 2026). Despite its non-binding nature, the opinion provides clarity to a controversy that had persisted for decades within the International Labour Organization (ILO), implicating its tripartite structure of government, employer, and worker representatives.

The Court was deliberate in circumscribing what its conclusion does and does not determine (International Court of Justice 2026, paras. 55–61). The recognition that the right to strike is protected under Convention Nº. 87 carries no determination as to its precise content, its scope, or the conditions for its lawful exercise (International Court of Justice 2026, para. 140). Those questions remain open to national regulation and oversight by ILO supervisory bodies, while the International Labour Conference may address the right to strike through future standard-setting, such as proposing a dedicated Convention.

BACKGROUND

The request for an advisory opinion was adopted by the ILO Governing Body on November 10, 2023, by 33 votes in favor, 21 against, and 2 abstentions, acting under Article 37(1) of the ILO Constitution and Article IX(2) of the UN–ILO Agreement (International Labour Organization 2023). The controversy is rooted in a textual gap: Convention Nº. 87 makes no explicit mention of the right to strike. Article 3(1) provides that workers’ and employers’ organizations shall have the right to “organise their administration and activities” and “formulate their programmes”, while Article 10 defines such organizations as bodies existing “for furthering and defending the interests” of their members. It remains uncertain whether strike action falls within the “ordinary meaning” of those terms.

Since 1989, the employer representatives within the Conference Committee on the Application of Standards—the International Labour Conference’s tripartite body that annually scrutinizes member-state compliance—had systematically challenged the position of the Committee of Experts on the Application of Conventions and Recommendations (CEACR), the ILO’s independent panel of jurists that monitors ratified conventions through state reports and has long held that Article 3 of Convention Nº. 87 encompasses the right to strike (International Court of Justice 2026, para. 49).

The employers’ group contested not only that substantive interpretation but also the CEACR’s authority to issue interpretations of ILO conventions—a power that Article 37(1) of the ILO Constitution reserves exclusively to the ICJ (International Labour Conference 2012, 9). The disagreement culminated at the 2012 International Labour Conference, when the employers’ and workers’ groups could not agree on the list of cases of non-compliance to be examined by the Committee, leaving it unable to exercise its supervisory functions in what the ILO itself characterized as an “institutional crisis”. Despite multiple rounds of tripartite negotiations over the subsequent fourteen years, no consensus proved attainable. The Governing Body ultimately voted, in 2023, to refer the question to the ICJ.

PARTICIPATION IN THE PROCEEDINGS

The advisory proceedings attracted a broad cast of participants. By its Order of 16 November 2023, the Court invited written contributions from the ILO itself, from all 158 States Parties to Convention Nº. 87, and from six organizations holding general consultative status with the ILO: on the employers’ side, the International Organisation of Employers and Business Africa; on the workers’ side, the International Trade Union Confederation, the World Federation of Trade Unions, the International Cooperative Alliance, and the Organisation of African Trade Union Unity (International Court of Justice 2023).

Unlike in Obligations of States in respect of Climate Change, where non-governmental organizations individually requested to participate, here the Court—at the ILO’s express request—granted participation to representative organizations holding consultative status, citing “the particular tripartite structure of the ILO” without further specifying the legal basis beyond a general reference to Article 66 (International Court of Justice 2023). The decision implicitly signals a broad reading of Article 66(2) of the ICJ Statute, which entitles the Court to notify any “international organization” considered likely to furnish relevant information. Unsurprisingly, the submissions of these organizations reflected the views of their respective constituents.

Out of the 158 states parties to the ILO Convention Nº. 87, 31 states and organizations submitted written statements, and the oral hearings held in October 2025 brought together 22 delegations. The United States and Brazil were admitted under Article 66(3) of the ICJ Statute to participate despite not being parties to Convention Nº. 87, on the basis of their ILO membership. Fifteen participants provided written comments on the first round of written statements, although the United States and the United Kingdom later withdrew their submissions.

While most states supported the view that the right to strike is protected under the ILO Convention Nº. 87, a minority—including Bangladesh, Costa Rica, Japan, and Switzerland—dissented from this position (International Court of Justice 2026, para. 95). These states converged on the argument that, since the words “strike” and “right to strike” appear nowhere in the Convention’s text and its preparatory work confirms that this omission was deliberate, no binding obligation regarding strike action can be derived from it. All four also rejected the CEACR’s progressive reading of strike-related rules as lacking the tripartite consensus required to constitute a legitimate interpretation of ILO Convention Nº. 87 under the Vienna Convention on the Law of Treaties (VCLT).

AN EXERCISE ON TREATY INTERPRETATION

The Court approached the request through two sequential steps: first, identifying the applicable rules of treaty interpretation, then applying them to the ILO Convention Nº. 87 (International Court of Justice 2026, para. 61). Given the absence of any explicit textual reference to the right to strike, the Court examined whether such a right could be inferred through the interpretive framework of the VCLT. While the VCLT does not formally apply to treaties concluded before its entry into force, the Court acknowledged that Articles 31–33 nonetheless reflect customary international law (International Court of Justice 2026, para. 62).

Applying Article 31(1) VCLT, the Court found that the silence of Convention Nº. 87 on the right to strike does not imply its exclusion (International Court of Justice 2026, para. 68). Read together, Articles 2, 3(1), and 10 indicate that workers have the right to form and join organizations in order to pursue and defend their interests, including through the organization of activities and the formulation of programs. A strike—a temporary collective work stoppage to enforce demands or support grievances—falls well within the ordinary meaning of “activities” (International Court of Justice 2026, para. 70). The limitations set out in Articles 8 and 9 (domestic law compliance; armed-forces and police exclusions) circumscribe but do not deny this reading (International Court of Justice 2026, para. 71).

Applying the principle of systemic integration under Article 31(3)(c) VCLT, the Court identified Article 8(1)(d) of the International Covenant on Economic, Social and Cultural Rights (ICESCR), which expressly protects the right to strike, and Article 22 of the International Covenant on Civil and Political Rights (ICCPR) as relevant rules of international law (International Court of Justice 2026, para. 91). The high degree of overlap between states parties to Convention Nº. 87 and those bound by the two Covenants, combined with the absence of objection among the handful of states parties to the Convention that have not ratified the Covenants, supported the Court’s inference of a common understanding that the right to strike is encompassed within Convention Nº. 87 (International Court of Justice 2026, para. 92).

Having satisfied itself that Article 31 yielded a clear answer (International Court of Justice 2026, para. 101), the Court proceeded to Article 32. The travaux préparatoires proved inconclusive, as the drafters had focused almost exclusively on the right to strike of public officials and left the general question open (International Court of Justice 2026, para. 111). The Court then turned to subsequent practice, which under Article 32 operates as a supplementary means of interpretation and does not require—as does Article 31—a “common understanding” among the parties. On that basis, the Court found that the treatment of Convention Nº. 87 by a significant majority of states parties as protecting the right to strike “is an element that must be taken into account as a supplementary means of interpretation” (International Court of Justice 2026, para. 115).

As a further supplementary means of interpretation, the Court ascribed “great weight” to the pronouncements of the ILO’s supervisory bodies—the CEACR, the Committee on Freedom of Association, and five Commissions of Inquiry—recognizing the right to strike as protected under Convention Nº. 87 (International Court of Justice 2026, para. 118). A survey of regional instruments, the Court added, showed that they “reveal a shared view” that “the protection of the right to strike is encompassed in the protection of the freedom of association” (International Court of Justice 2026, para. 137). The European Court of Human Rights has construed Article 11 of the European Convention as protecting the right to strike as a “core element” of freedom of association, and the Court of Justice of the European Union has recognized it as a fundamental right with explicit reference to Convention Nº. 87 (Court of Justice of the European Union 2007). The Inter-American Court of Human Rights, in Advisory Opinion OC-27/21 and in Former Employees of the Judiciary v. Guatemala, declared freedom of association, collective bargaining, and the right to strike to be “interdependent and indivisible” (Inter-American Court of Human Rights 2021).

Four judges—Abraham, Hmoud, Tomka, and Xue—dissented from the majority’s conclusion, recalling that clear and persistent objections by several states parties precluded any finding of a common understanding among all parties (Abraham 2026; Hmoud 2026; Tomka 2026; Xue 2026). All four agreed that a rigorous application of Articles 31–32 VCLT does not support including the right to strike within the Convention’s scope, emphasizing that the ordinary meaning of terms such as “activities” and “programmes” in Article 3(1) does not compel such a reading. They also rejected the majority’s invocation of the ICESCR and ICCPR as “relevant rules of international law” under Article 31(3)(c), noting that those instruments form separate treaty regimes not binding on all parties to Convention Nº. 87, and that the ICESCR’s separate enumeration of the right to strike reinforces the distinction between that right and freedom of association.

CONCLUSION

The Court’s opinion carries normative and political weight well beyond the ICJ itself. Within the ILO, it may finally dissolve the interpretive impasse that has paralyzed the supervisory system since 2012. With an authoritative opinion in hand, employer representatives will find it harder to contest the CEACR’s reading of Convention Nº. 87. More broadly, the opinion vindicates what trade unions and workers’ movements have long argued: that freedom of association cannot be meaningfully guaranteed without workers’ ability to suspend their labor temporarily. Though formally non-binding, the opinion will likely reverberate across labor standards, industrial relations, and international trade discussions worldwide. What it does not settle are the precise contours of the right and the conditions under which its exercise is lawful—questions that remain largely matters of domestic law.

References

Abraham, Ronny. 2026. “Dissenting Opinion.” Right to Strike under the Freedom of Association and Protection of the Right to Organise Convention, 1948 (No. 87) (Advisory Opinion). International Court of Justice, May 21. https://www.icj-cij.org/sites/default/files/case-related/191/191-20260521-adv-01-04-fr.pdf.

Bangladesh. 2024. “Written Statement.” Right to Strike under ILO Convention No. 87 (Advisory Opinion). International Court of Justice, May 16. https://www.icj-cij.org/sites/default/files/case-related/191/191-20240516-wri-04-00-en.pdf.

Costa Rica. 2024. “Written Statement.” Right to Strike under ILO Convention No. 87 (Advisory Opinion). International Court of Justice, May 14. https://www.icj-cij.org/sites/default/files/case-related/191/191-20240514-wri-03-00-en.pdf.

Court of Justice of the European Union. 2007. Laval un Partneri Ltd v. Svenska Byggnadsarbetareförbundet. Case C-438/05. https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:62005CJ0438.

Hmoud, Mahmoud D. 2026. “Dissenting Opinion.” Right to Strike under ILO Convention No. 87 (Advisory Opinion). International Court of Justice, May 21. https://www.icj-cij.org/sites/default/files/case-related/191/191-20260521-adv-01-11-encc.pdf.

Inter-American Court of Human Rights. 2021. Advisory Opinion OC-27/21. San José: IACtHR. https://www.corteidh.or.cr/docs/opiniones/seriea_27_ing.pdf.

International Court of Justice. 2023. Order of 16 November 2023. Request for an Advisory Opinion (Right to Strike under ILO Convention No. 87). https://icj-cij.org/sites/default/files/case-related/191/191-20231116-ord-01-00-en.pdf.

International Court of Justice. 2025. Obligations of States in respect of Climate Change. Advisory Opinion. https://www.icj-cij.org/case/187.

International Court of Justice. 2026. Right to Strike under the Freedom of Association and Protection of the Right to Organise Convention, 1948 (No. 87). Advisory Opinion of 21 May 2026. https://www.icj-cij.org/sites/default/files/case-related/191/191-20260521-adv-01-00-en.pd.

International Labour Conference. 2012. The Standards Initiative: Interpretation of International Labour Conventions (Article 37 of the ILO Constitution). Geneva: ILO. https://www.ilo.org/sites/default/files/wcmsp5/groups/public/%40ed_norm/%40relconf/documents/meetingdocument/wcms_205472.pdf.

International Labour Organization. 1948. Freedom of Association and Protection of the Right to Organise Convention (No. 87). Geneva: ILO. https://normlex.ilo.org/dyn/nrmlx_en/f?p=NORMLEXPUB:12100:0::NO::P12100_INSTRUMENT_ID:312232.

International Labour Organization. 2021. Constitution of the International Labour Organization. Geneva: ILO. https://www.ilo.org/sites/default/files/2024-04/ILO%20Constitution-2021-%5BJUR-210720-001%5D-Web-EN.pdf.

International Labour Organization. 2023. Decision to Refer to the International Court of Justice the Question of the Right to Strike (Governing Body, 10 November 2023). Geneva: ILO. https://www.ilo.org/sites/default/files/wcmsp5/groups/public/%40dgreports/%40dcomm/documents/genericdocument/wcms_902030.pdf.

Japan. 2024. “Written Statement.” Right to Strike under ILO Convention No. 87 (Advisory Opinion). International Court of Justice, May 16. https://www.icj-cij.org/sites/default/files/case-related/191/191-20240516-wri-11-00-en.pdf.

Switzerland. 2024. “Written Statement.” Right to Strike under ILO Convention No. 87 (Advisory Opinion). International Court of Justice, May 6. https://www.icj-cij.org/sites/default/files/case-related/191/191-20240506-wri-02-00-en.pdf.

Tomka, Peter. 2026. “Dissenting Opinion.” Right to Strike under ILO Convention No. 87 (Advisory Opinion). International Court of Justice, May 21. https://www.icj-cij.org/sites/default/files/case-related/191/191-20260521-adv-01-03-en.pd.

United Nations. 1945. Statute of the International Court of Justice. San Francisco: United Nations. https://www.icj-cij.org/statute.

United Nations. 1966a. International Covenant on Civil and Political Rights. Treaty Series 999. New York: United Nations.

United Nations. 1966b. International Covenant on Economic, Social and Cultural Rights. Treaty Series 993. New York: United Nations.

United Nations. 1969. Vienna Convention on the Law of Treaties. Treaty Series 1155. Vienna: United Nations.

United Nations and International Labour Organization. 1946. Agreement between the United Nations and the International Labour Organisation. https://www.ilo.org/sites/default/files/wcmsp5/groups/public/%40dgreports/%40jur/documents/genericdocument/wcms_433792.pdf.

Xue, Hanqin. 2026. “Dissenting Opinion.” Right to Strike under ILO Convention No. 87 (Advisory Opinion). International Court of Justice, May 21. https://www.icj-cij.org/sites/default/files/case-related/191/191-20260521-adv-01-05-en.pd.

Submitted: June 11 2026

Accepted for publication: June 15, 2026

Copyright © 2026 CEBRI-Journal. This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original article is properly cited.