The International Court of Justice delivered an Advisory Opinion in May 2026 answering a question that had divided the International Labour Organization for over a decade: yes, the right to strike is protected by ILO Convention 87 on freedom of association.

The question was deceptively simple, and the Convention's text was silent on the answer. The word 'strike' does not appear anywhere in Convention 87, adopted in 1948 and currently ratified by 157 of the ILO's 187 member states. The Convention protects freedom of association for workers and employers and guarantees the right 'to organise their activities'. Whether that phrase implicitly covers the right to strike was the issue put to the Court.

The vote was 10 to 4. An overwhelming majority of the Court's 14 judges sided with the reading long advanced by the ILO's own supervisory bodies. Although an Advisory Opinion is not legally binding, it carries significant authority, and the ILO Governing Body, which requested it in 2023 on a resolution submitted by the Workers' Group, is expected to respond when it meets in November 2026.

Sixty Years of Settled Interpretation

For decades, the Convention's silence caused no difficulty. The ILO's internal supervisory bodies — the independent Committee of Experts and the tripartite Committee on Freedom of Association (CFA) — consistently interpreted the freedom to 'organise their activities' as implicitly including the right to strike. Regional human rights courts across Europe, the Americas and Africa adopted the same reading. It became the dominant doctrine of international labour law.

That consensus broke in 2012. The ILO Employers' Group objected to the interpretation, arguing that the word 'strike' does not appear in the Convention and that no evidence shows the drafters intended to include it. By objecting loudly and repeatedly, the Employers' Group achieved something significant: it could now claim that 'the ILO' itself was divided on the matter. The objection undermined the authority of an interpretation that had stood for 60 years.

The ILO spent 11 years trying to resolve the dispute through internal dialogue, its customary route for settling disagreements among its tripartite constituents of workers, employers and governments. That approach failed this time. In 2023, the Workers' Group secured passage of a resolution in the Governing Body referring the question to the ICJ, despite objections from the Employers' Group and several member states.

A Methodical Piece of Treaty Interpretation

The Court's reasoning closely follows the rules of the 1969 Vienna Convention on the Law of Treaties. It examined the ordinary meaning of the words 'to organize activities', the context in which Convention 87 was adopted in 1948, and the Travaux Préparatoires recording the drafting process. It also studied the interpretation the treaty has received from the ILO supervisory committees over the decades.

The Court noted that the right to strike is explicitly mentioned in Article 8 of the International Covenant on Economic, Social and Cultural Rights of 1966, which addresses freedom of association. It further surveyed how regional human rights courts and supervisory committees across four continents have consistently treated ILO Convention 87 as the legal basis for the right to strike. In doing so, the Court attached 'great weight' to the interpretations of the ILO supervisory committees — an important endorsement of the supervisory system itself.

A Clear but Carefully Defined Holding

The conclusion was clear, but its boundaries were carefully drawn. The Court confirmed that the right to strike forms part of Convention 87. It said nothing about what that right looks like in practice — whether civil servants may strike, whether workers in essential services are covered, or what restrictions states may impose.

Those practical questions, which matter most in day-to-day legal practice, fall to the CFA, whose accumulated guidance appears in the Compilation of CFA Decisions. Those decisions were adopted before 2012 in consensus among the ILO's three constituent groups, and the Court's deference to supervisory committee interpretations suggests they will hold up firmly.

What Happens Next

The Opinion is non-binding but authoritative. Thirty-two member states participated in the proceedings before the ICJ with oral and written statements, and most will likely argue that the dispute should now end. Whether the Employers' Group accepts the Court's ruling or continues to contest it within the ILO remains to be seen.

For labour practitioners, the practical consequence is straightforward. The ICJ has placed its authority behind the proposition that Convention 87 protects the right to strike, closing off the textual argument that the Employers' Group pressed since 2012. Counsel advising unions, employers or governments on strike legality in the 157 ratifying states can now cite the ICJ's endorsement of the supervisory committees' longstanding reading, while detailed questions of scope and restriction continue to be governed by CFA case law and national law.

The ILO Governing Body meets in November 2026, and a formal response to the Opinion is expected then.