By judgment of 11 December 2025, the Court of Justice of the European Union ruled on the determination of the law applicable to an employment contract presenting cross-border elements, pursuant to Article 6 of the Rome Convention on the law applicable to contractual obligations, opened for signature in Rome on 19 June 1980 (“Rome Convention”).

As is well known, for contracts concluded after 17 December 2009, the law applicable to cross-border contractual obligations is governed by Regulation (EC) No 593/2008 of the European Parliament and of the Council of 17 June 2008 (“Rome I”). In the present case, however, the employment contract had been concluded on 15 October 2002; therefore, the Rome Convention applies ratione temporis. For the purposes relevant here, its provisions were not substantially amended by the Rome I Regulation.

Article 6 of the Rome Convention (now replaced by Article 8 of the Rome I Regulation) provides that an employment contract is governed by the law chosen by the parties. However, even where the parties have agreed on the application of the law of a given country, such choice shall not have the result of depriving the employee of the protection afforded to him by the provisions of the law which cannot be derogated from the law of the country in which the employee habitually carries out his or her work (Art. 6(2) let. a)) or, if the employee does not habitually carry out his work in any one country, of the law of the country in which the employer’s place of business that engaged the employee is situated (Art. 6(2) let. b).

Within this legal framework, Mr ES, a French national, entered into an employment contract with Locatrans, a transport company established in Luxembourg. The parties agreed that Luxembourg law would govern the employment contract. In an initial phase of the employment relationship, Mr ES carried out his work in several countries. Subsequently, his work was performed predominantly in France, to the extent that Locatrans registered him with the French social security system. Following Mr ES’s dismissal by Locatrans, he brought proceedings before the French courts challenging the termination of his employment contract, claiming that it was unlawful under the mandatory provisions of French law, which he considered applicable on the ground that his work had been habitually carried out in France.

In this factual context, the Paris court referred a question to the Court of Justice for a preliminary ruling, asking whether Article 6(2)(a) and (b) of the Rome Convention must be interpreted as meaning that, where an employee, after having carried out his work for a certain period in a given place, is required to perform his activities in another place intended to become the new habitual place of work, that latter place must be taken into account for the purpose of determining the mandatory rules protecting the employee.

The Court of Justice held that the connecting factor of the place where the employee habitually carries out his work shall be determined by considering the employment relationship as a whole. Where, during the employment relationship, a change occurs with regard to the habitual place of performance of work, it is not possible to identify a single country for the purposes of applying Article 6(2)(a) of the Rome Convention. In such circumstances, the employee may benefit solely from the mandatory rules of the law of the country in which the place of business through which he was engaged is situated, pursuant to Article 6(2)(b), namely, in the present case, Luxembourg law.

It follows that, since the parties had already chosen Luxembourg law as the law applicable to the employment contract, the employee may not rely on the protection afforded by mandatory rules other than those provided for under Luxembourg law.

 

(Comment by Pietro Campana)