What does Union citizenship, traditionally dependent on a cross-border element, offer to those who have never exercised their right to free movement and have always resided in their Member State of nationality? For more than a decade, the position of these so-called “static Union citizens” has remained largely confined to the exceptional protection recognised in Ruiz Zambrano (Case C-34/09). In its recent judgment in Safi (Case C-147/24), delivered on 4 June 2026, the ECJ extended those limits, relying in particular on the Charter of Fundamental Rights (Charter). The judgment established that Union citizenship not only protects static minor Union citizens from being compelled to leave the Union as a whole, but also from being forced to move within the Union. In doing so, the Court implicitly recognised a negative dimension of free movement, or, put more aptly, a right not to move.

From Ruiz Zambrano to Safi

Any analysis of Safi must begin with Ruiz Zambrano, the landmark case for the rights of static Union citizens. In principle, the exercise of rights derived from Union citizenship presupposes a cross-border element, thus offering little, if any, protection for static citizens. Ruiz Zambrano carved out an important exception by extending the protection of Union citizenship to non-movers where they would otherwise be deprived of the genuine enjoyment of the substance of rights attached to that status (para. 42).

The case concerned the residence rights of a third-country national (TCN) parent of minor Union citizens who had never exercised their right to free movement and had always resided in the Member State of which they were nationals. Despite the purely internal nature of the situation, the Court held that Art. 20 TFEU required the parent to be granted a derived right of residence in the Member State of nationality of his Union citizen children. Because the children were dependent on their TCN parent, refusing the parent residence would, in practice, compel the children to accompany him and leave the territory of the Union. The Court concluded that compelling a Union citizen to leave the EU territory would deprive them of the genuine enjoyment of the substance of their citizenship rights (para. 44), thereby recognising a right to reside within the Union that also protects non-moving Union citizens.

While the indeterminate substance of rights formula sparked a lively debate in academia on how to transform Union citizenship into a more meaningful and universal status (see here and here), the ECJ reinforced the exceptional nature of the substance of rights test in its subsequent case law, keeping it confined to residence rights for TCN parents of dependent minor Union citizens (see Dereci and Chávez-Vílchez). Ruiz Zambrano had therefore evolved from a potentially transformative principle into a narrow safety net protecting minor Union citizens against being forced out of the Union.

Safi brought before the Court the question whether this protection against involuntary relocation also extends to relocations within the EU. Although the Court’s earlier case law (see Alokpa, M.D. and Rendón Marín) suggested that the protection was confined to situations in which Union citizens would be compelled to leave the EU territory altogether, Safi was the first case in which the Court was directly asked to determine whether Art. 20 TFEU also protects Union citizens who would otherwise be forced merely to relocate to another Member State.

Facts of the Case

Safi concerned the residence rights of a Moroccan mother who had lived in the Netherlands since 2014 with her Dutch-Moroccan husband and their Dutch son, who was born there in 2015. Yet, she had never obtained a Dutch residence permit. Owing to health issues, her husband did not work and had been partially exempted from the obligation to do so. He therefore relied on social assistance benefits. Their son, who was cared for by both his parents, had speech and language difficulties, for which he attended a specialised educational institution. He had never lived outside the Netherlands.

In 2020, the mother applied for certification of her derived right of residence based on her son’s Union citizenship. The Dutch authorities rejected her application and ordered her to return to Spain, where she had lived based on a right of residence before joining her husband in the Netherlands. She challenged this decision before the national courts and claimed to have renounced her right of residence in Spain. The domestic court stayed the proceedings and requested a preliminary ruling from the ECJ.

A Right Not to Move: Opinion of Advocate General Ćapeta

AG Ćapeta argued in favour of awarding the mother a derived right of residence based on the child’s right not to move under Art. 20 TFEU. In her Opinion, she submitted that the substance of rights attached to Union citizenship encompassed not only a right to reside within the territory of the EU, but also a right not to move within the EU (para. 56). As in Ruiz Zambrano, this right not to move would be infringed where the TCN parent of a dependent minor Union citizen would be denied a derived right of residence (paras 87–113).

Her reasoning proceeded along two principal lines. First, she advanced a textual argument, contending that a right to move freely necessarily presupposed a right to choose not to move (paras 57–59). The freedom of movement would otherwise be turned from a right into an obligation.

Second, the AG placed this interpretation within her understanding of the nature of Union citizenship. She argued that if Union citizenship was to constitute the “fundamental status of all nationals of the Member States” (Commission v Malta, para. 92), it also had to be relevant to the overwhelming majority of Union citizens who have never exercised free movement (paras 60–70). Referring to a “wider European society based on common values” (para. 70), she characterised Union citizenship as the principal legal bond linking both static and mobile individuals to that community.

This status-based approach also informed her understanding of the Charter’s scope of application. In her view, the Charter became applicable by virtue of an individual’s status as a Union citizen, without requiring a further link to EU law (para. 104). Despite this far-reaching proposal, the Charter played no significant role in the Opinion, since the AG derived the right not to move directly from Art. 20 TFEU.

Citizenship as a Gateway to Charter Protection: The Court’s Judgment

The ECJ’s judgment, by contrast, is much more informed by fundamental rights. Although it reached substantially the same outcome, strongly pointing towards an obligation of the Netherlands to grant the mother a derived right of residence, the Court avoided engaging with the AG’s status-based reasoning.

The Court first considered the scenario where the applicant no longer enjoyed a right of residence in Spain, such that the refusal of a derived right of residence would compel her to leave the territory of the Union altogether. As this scenario fell squarely within the Ruiz Zambrano case law, the dependency between mother and son would require the Dutch authorities to grant the mother a derived right of residence (paras 41–49).

Regarding the novel question whether the same would follow if she could lawfully reside in Spain, the Court first established an interference with Union citizenship. It observed that, given the son’s dependency on his mother, requiring her to relocate to Spain would effectively force him to follow (para. 51). According to the Court, this would interfere with his right to move and reside freely under Art. 20(2)(a) TFEU (para. 54). Although the judgment is rather laconic on this point, we find it difficult to read this passage as anything other than an implicit recognition of a negative dimension of free movement or, in AG Ćapeta’s words, a right not to move. It accepted that the right to move and reside freely is affected where a Union citizen is compelled to leave their Member State of nationality.

The interference with Art. 20(2)(a) TFEU situated the case within the scope of EU law, paving the way for the application of the Charter under Art. 51(1). The consequences of the child’s possible relocation therefore had to be assessed in light of his right to family life and his best interests under Art. 7 and 24(2)(3) of the Charter. Art. 7, read together with Art. 24(3), protects the child’s right to maintain a personal relationship and direct contact with both parents. Since the father’s inability to work made it unlikely that he could lawfully reside in Spain (see Art. 7 of the Citizenship Directive), the child’s relocation ran the risk of separating him from his father in violation of his right to family life (paras 57–60). Due to his lack of proficiency in Spanish and his existing speech and language difficulties, the Court considered the relocation particularly disruptive and therefore also contrary to the child’s best interests protected by Art. 24(2) (paras 62–63). Subject to the referring court’s verification of the relevant facts, the judgment therefore strongly pointed towards an obligation to grant the mother a derived right of residence in the Netherlands (para. 65).

A Right Not to Move Through the Charter

Safi undoubtedly strengthened the protection of static Union citizens. Whereas the Court’s earlier case law had suggested that the protection against involuntary relocations was confined to situations in which Union citizens would be compelled to leave the EU territory altogether, Safi extended this protection to forced intra-EU movement. Yet, it did so by a doctrinal route different from that envisaged by AG Ćapeta. Starting from the premise that Union citizenship is the fundamental status of all Member State nationals, the AG considered an autonomous right not to move as part of the substance of citizenship rights. She thus sought to extend the Ruiz Zambrano doctrine from forced departure from the Union to compelled movement within it.

The ECJ reached a substantially similar outcome without extending the substance-of-rights test. Although it cited the Ruiz Zambrano case law (para. 34), it did not hold that forced intra-EU relocation, as such, deprived a citizen of the substance of Union citizenship rights. Instead, it relied on the interference with the child’s right under Art. 20(2)(a) TFEU to bring the case within the scope of EU law and, consequently, within the scope of the Charter. Art. 7 and 24 of the Charter then supplied the substantive standards for assessing the consequences of relocation for the child’s family life and best interests. In doing so, the Court was able to avoid reopening the notoriously expansive and contested substance-of-rights test.

Union citizenship therefore performed a gateway function in Safi. The Court implicitly recognised the functional equivalent of a right not to move, but ultimately relied on fundamental rights rather than Union citizenship status. Safi should accordingly be understood neither as a straightforward extension of Ruiz Zambrano nor as an abandonment of its protective rationale. The continuity lies in the protection of dependent Union citizen children against the practical consequences of residence decisions concerning their TCN parents while the innovation lies in the Charter-based mechanism through which that protection is secured.

This approach also matters beyond the immediate case. In line with Wojewoda Mazowiecki and Mirin, Safi illustrates the increasingly close relationship between Union citizenship and EU fundamental-rights protection, with citizenship rights providing the jurisdictional basis for reviewing national measures under the Charter. Yet the Court retains a limiting criterion: the Charter is triggered only by interference with a specific EU citizenship right, not by Union citizen status alone as envisaged by the AG. It thereby avoids turning Union citizenship into a “master key” capable of bringing any situation involving a Member State national within the scope of EU law (see here).

The judgment was therefore both cautious and original. It preserved the narrow scope of the Ruiz Zambrano doctrine while construing a targeted route from Union citizenship to Charter protection against compelled intra-EU relocation.