On 21 May 2026, the International Court of Justice (ICJ), based in The Hague, issued an Advisory Opinion determining that the right to strike is internationally protected under Convention 87 of the International Labour Organization (ILO) concerning freedom of association.
In its operative clause, the ICJ decision states:
“By ten votes to four, it is of the opinion that the right to strike of workers and their organizations is protected under the Convention concerning Freedom of Association and Protection of the Right to Organise, 1948 (No. 87).”
Although this is an advisory opinion, not a binding judgment, the legal, institutional, and ethical weight of the decision is indisputable and, in fact, closes a dispute that had been ongoing within the International Labour Organization since 2012.
Background
In its decision, the ICJ provides a brief summary of the background, noting that as early as 1952, the Committee on Freedom of Association (CFA) affirmed that the right to strike is an essential component of trade union rights.
Similarly, the Committee of Experts on the Application of Conventions and Recommendations (CEACR) has repeatedly held that Article 3 of Convention No. 87 includes the recourse to strike.
However, employers’ representatives within the ILO challenged in various forums and at different times whether the Convention protects this right, while workers’ representatives defended the position of the Committee of Experts.
Faced with the failure of internal negotiations, the Governing Body referred the matter to the Court under Article 37 of the ILO Constitution.
This article provides as follows:
“All questions or difficulties relating to the interpretation of this Constitution or of any subsequent convention concluded by the Members under the provisions of this Constitution shall be referred to the International Court of Justice for decision (…) Any award or advisory opinion of the International Court of Justice shall be binding upon any tribunal established under this paragraph. Any judgment rendered by such a tribunal shall be communicated to the Members of the Organization, and any observations they make thereon shall be submitted to the Conference.”
The procedure was initiated following a request from the ILO Director-General to the ICJ President via a letter dated 13 November 2023, after which the Court organised the proceedings.
The Director-General implemented the resolution of the ILO Governing Body which, at its 349th session on 10 November 2023, decided (after many years of debate) on the basis of Article 37 of the ILO Constitution and Article 65, paragraph 1, of the ICJ Statute, as well as Article 103 of the Court’s Rules, to request an advisory opinion from the ICJ based on the following question:
“Is the right to strike of workers and their organisations protected under the Convention concerning Freedom of Association and Protection of the Right to Organise, 1948 (No. 87)?”
Reasoning
In its decision, the ICJ details the interpretative criteria used for its ruling.
It states that it applies Articles 31 and 32 of the 1969 Vienna Convention on the Law of Treaties.
This aspect is very relevant because proposals had been received to reject the application of the Vienna Convention due to the tripartite and therefore different nature of the ILO, arguing that for this reason priority should be given to preparatory discussions over the finally adopted treaty text. However, while the ICJ takes those records into account, it understands them as complementary to, not a substitute for, the existing international norm.
Regarding the substance of the question submitted for its consideration, the ICJ, by a large majority, holds that although Convention No. 87 does not expressly mention the right to strike, the jurisprudence of the ICJ consistently affirms that the absence of an express clause does not automatically imply the exclusion of a matter. Such an exclusion would only be valid if deduced from a comprehensive examination of the provisions, their context, and the object and purpose of the treaty.
The ICJ carries out an integrated interpretation of Articles 2, 3, and 10 of Convention No. 87: while Article 2 enshrines the right to form organisations, Article 3 establishes that those same entities may “organise their activities and formulate their programmes”, while Article 10 conceptualises these organisations as those having the objective of “furthering and defending the interests of workers or of employers”.
The ICJ understands that the terms “activities” and “programmes” must include the wide range of actions that unions use collectively, with the strike being one of the habitual and essential actions for any labour organisation.
It reinforces these ideas by recalling that Convention No. 87 only includes restrictions linked to compliance with national or local laws and in relation to the armed forces and the police, but there is no clause from which the exclusion of the strike from the activities mentioned in Article 3 could be grounded.
Additionally, the Court recalls that the preamble of Convention No. 87 invokes the ILO Constitution and the Declaration of Philadelphia, which commit to the defence of freedom of association, for which the exercise of the right to strike has key value as an indispensable tool for its effectiveness.
As a result of this reasoning, the ICJ affirms that the protection of the right to strike is subsumed under the guarantees of freedom of association.
Reactions
The International Labour Office issued a statement informing that it had received formal notification of the ICJ’s Advisory Opinion.
Without commenting on its content, it recalled that this was only the second referral of this type in the ILO’s history. The first request was made in 1932 to the Permanent Court of International Justice, the ICJ’s predecessor, concerning the interpretation of the Convention concerning Night Work (Women), 1919 (No. 4).
For its part, the International Trade Union Confederation (ITUC) expressed satisfaction with the ICJ’s decision, as it confirms the vision of the world’s trade unions in understanding that the right to strike is protected by Convention 87 on freedom of association and the protection of the right to organise.
The ITUC argues that the ICJ’s opinion reaffirms decades of consistent international labour jurisprudence and restores legal certainty and credibility within the international labour standards system.
The right to strike is an essential component of freedom of association and a fundamental means by which workers defend their interests, secure decent work, and contribute to democratic societies; therefore, the ITUC understands that the decision is a victory for the ILO as a whole.
Looking to the future, the trade union organisation hopes that work will be done to ensure that the ILO’s supervisory system fully resumes its work of guiding governments in the application of Convention 87, including the right to strike.
The Trade Union Confederation of the Americas issued a statement with similar content to the ITUC, adding that:
“In an international context marked by the advance of authoritarian projects, attacks on freedom of association, criminalisation of social protest, and deepening inequalities, the reaffirmation of this right acquires even greater importance for the peoples of Latin America and the Caribbean.”
Relevance of the Decision
The unappealable opinion of the ICJ has high value, especially at the political and institutional level, as it resolves the controversy raised by the business sector (recalling the tripartite nature of the ILO), which was supported by some governments and always opposed by workers’ representatives.
During the hearings held in 2025, this divergence of positions became evident. For example, in the case of the Americas, the delegation of Costa Rica understood that the right to freedom of association does not refer to or expressly contemplate the right to strike in its fundamental conventions or its constitution. Unlike the right to freedom of association and the right to collective bargaining, according to the Costa Rican opinion, there is no ILO convention that specifically refers to the right to strike.
In contrast, the submissions from Colombia and Mexico argued a position opposite to that of Costa Rica.
Colombia, citing the Committee on Freedom of Association, considered the right to strike as intrinsic to the right to freedom of association and collective bargaining. Therefore, it adopted the position of the Workers’ Group regarding the protection of the right to strike through Convention No. 87, as consistently held in Colombian jurisprudence.
Similarly, the communication from the Government of Mexico considered that the right to strike is protected by Convention No. 87 concerning freedom of association and the protection of the right to organise, due to an inexorable relationship between the right to organise and the right to strike, in which the existence of one invariably implies the existence of the other.
Verbally, the delegation of the Eastern Republic of Uruguay supported the position defended by Colombia and Mexico.
It is to be expected that after the ICJ’s opinion is known, denialist positions will not be supported by any government, and the same should happen within the International Labour Organization.
Although the right to strike is enshrined as a fundamental right in international legal instruments such as the UN Covenant on Economic, Social and Cultural Rights, as well as in multiple national constitutions, the resolution of this controversy will allow the full application of the ILO’s control mechanisms related to freedom of association without any argument to the contrary regarding the inclusion of the full exercise of the right to strike among the aspects to be supervised.
From a broad geopolitical perspective, it must be considered that the ICJ’s ruling adds to the promotion and protection of individual and collective human rights in a context of evident deterioration of the international system and multilateralism as a whole.