Consequences of the International Court of Justice Opinion on the Right to Strike

On 21 May 2026, the International Court of Justice (ICJ) confirmed that the right to strike is protected by Convention No. 87 of the International Labour Organization (ILO). This decision fundamentally changes the legal debate : it no longer concerns the existence of the right to strike, but rather the permissible limits on its exercise.

A Weakened Swiss Position

Before the advisory opinion of the International Court of Justice, the Swiss government and employers’ organizations maintained that Convention No. 87 did not directly protect the right to strike.

In its written submission of 6 May 2024, the Swiss Confederation argued in particular that the Convention does not explicitly mention the word « strike », that the preparatory work did not support including such a right, and that the ILO supervisory bodies did not possess autonomous interpretative authority.

Swiss submission :
https://icj-web.leman.un-icc.cloud/sites/default/files/case-related/191/191-20240506-wri-02-00-fr.pdf

The International Court of Justice rejected that conclusion.

It confirmed that the right to strike is indeed protected by Convention No. 87.

A Major Reinforcement for Trade Unions

Trade union organizations now possess a legal argument of the highest importance.

They may jointly invoke :

Convention No. 87 ;
the advisory opinion of the International Court of Justice ;
the case law of the Committee on Freedom of Association ;
the observations of the Committee of Experts on the Application of Conventions and Recommendations.

ILO documentation :
https://normlex.ilo.org

This combination should strengthen trade union complaints submitted to ILO bodies.

The Focus of the Debate Shifts

Before 21 May 2026, the central question was :

Does Convention No. 87 protect the right to strike ?

Following the opinion of the International Court of Justice, the question becomes :

Which restrictions on the right to strike are compatible with Convention No. 87 ?

The debate now concerns :

proportionality ;
essential services ;
conciliation procedures ;
sanctions against strikers ;
restrictions applicable to public employees.

A Likely Influence on Swiss Courts

The advisory opinion of the International Court of Justice is not formally legally binding in the same way as a judgment.

However, its authority is considerable.

The Swiss Federal Supreme Court regularly takes into account international law, conventions ratified by Switzerland, and interpretations provided by international tribunals.

Swiss Federal Supreme Court :
https://www.bger.ch

Convention No. 87 :
https://normlex.ilo.org/dyn/normlex/fr/f?p=NORMLEXPUB:12100:0::NO::P12100_ILO_CODE:C087

It will therefore become difficult for a Swiss court to ignore the fact that the world’s highest international court has recognized that Convention No. 87 protects the right to strike.

Switzerland’s Partial Institutional Victory

Employers’ organizations and Swiss authorities did not lose on every point.

The International Court of Justice did not recognize an autonomous law-making power for the ILO supervisory bodies.

It recalled that the interpretation of an international convention must be carried out in accordance with the general rules of treaty law.

These rules are set out in particular in Articles 31 and 32 of the Vienna Convention on the Law of Treaties.

Vienna Convention :
https://legal.un.org/ilc/texts/instruments/french/conventions/1_1_1969.pdf

This means that the Committee of Experts on the Application of Conventions and Recommendations and the Committee on Freedom of Association cannot simply assert that an obligation exists.

They must base their reasoning on :

the text ;
the context ;
the object ;
the purpose ;
subsequent practice ;
the preparatory work.

Swiss Industrial Peace Is Not Abolished

The opinion of the International Court of Justice does not abolish the Swiss model of social partnership.

It does not call into question :

Article 28 of the Federal Constitution ;
collective bargaining agreements ;
industrial peace obligations ;
conciliation procedures ;
the principle of proportionality.

Federal Constitution, Article 28 :
https://www.fedlex.admin.ch/eli/cc/1999/404/fr#art_28

The Court recognizes the right to strike.

It does not recognize an unlimited right to strike.

A Strategic Consequence for Swiss Trade Unions

For the Swiss Trade Union Federation, Unia, Syndicom, the Transport Personnel Union, the Public Services Union, the Interprofessional Union of Workers, and Travail.Suisse, the opinion of the International Court of Justice becomes a major legal reference.

Any Swiss reform or practice that excessively restricts the right to strike may now be challenged on the basis of :

Convention No. 87 ;
the advisory opinion of 21 May 2026 ;
the consistent case law of the ILO.

This concerns in particular situations where :

strikes are made practically impossible ;
sanctions against strikers are disproportionate ;
certain categories of workers are deprived of any effective possibility of striking.

Conclusion

Employers’ organizations and Swiss authorities lost on the fundamental issue :