Free movement of persons and citizenship

Free movement of persons is the point at which EU constitutional law becomes visibly social. Weeks 1–5 established the architecture: sources, institutions, supremacy, direct and indirect effect, state liability, and the market logic of free movement of goods. Week 6 applies those constitutional tools to human movement. The topic is not merely immigration law. It concerns the allocation of status, rights and public welfare across a legal order in which nationals of Member States are also Union citizens.

The modern law has two intertwined strands. First, there is the economic free movement of workers, self-employed persons and service providers. Its Treaty basis lies principally in Articles 45, 49 and 56 TFEU. The worker line of authority is generous: a person may be a worker if their activity is genuine and effective, even if part-time, low-paid, or supplemented by public funds. Secondly, there is Union citizenship under Articles 20 and 21 TFEU, supplemented by Directive 2004/38. Citizenship initially appeared to constitutionalise free movement beyond the market, but the Court of Justice has moved between expansive and restrictive phases. Grzelczyk and Baumbast suggested that Union citizenship could be the fundamental status of nationals of the Member States. Dano, Alimanovic and Commission v United Kingdom reveal a more conditional model, particularly where economically inactive citizens claim social assistance.

For a Durham first-year paper, the core examination skill is to avoid treating the topic as a list of entitlements. It is a structured constitutional field. Ask: who is moving; in what capacity; for how long; against whom is the right invoked; what is the source of the right; is the measure discriminatory or restrictive; and can the host State justify it? A strong answer integrates doctrinal technique from earlier weeks. Article 45 TFEU is directly effective; Directive 2004/38 governs residence and equal treatment; proportionality is the principal judicial method; and supremacy explains why conflicting national rules had to yield before Brexit.

In the UK context, the position is now bifurcated. For historical examination of EU law, the pre-Brexit position remains central: EU free movement rights operated domestically through the European Communities Act 1972, especially section 2(1). After Brexit, free movement of persons has ended for most new arrivals, but retained EU law, assimilated law, and the Withdrawal Agreement continue to matter for accrued rights and for interpretation. Do not allow Brexit to erase the doctrinal law: most EU Constitutional Law examinations still test the classic EU principles, while expecting students to recognise the altered domestic status of those principles.

The Treaty of Rome conceived free movement of persons primarily as a market freedom. The worker was a factor of production. Article 48 EEC, now Article 45 TFEU, prohibited nationality discrimination as regards employment, remuneration and other working conditions. The initial legal imagination was economic: the common market required labour mobility just as it required the movement of goods, services and capital. That explains why early cases such as Levin, Kempf and Lawrie-Blum concentrate on the definition of a worker and the reality of economic activity.

The story then widens. The Court of Justice adopted an autonomous EU concept of worker, preventing Member States from defining the term narrowly to protect domestic labour markets or welfare systems. At the same time, secondary legislation developed rights of entry, residence, family reunification and equal treatment. These rights were not decorative. Without family rights, the right to move would be unattractive; without equal treatment, migrant workers could be deterred by discriminatory burdens; without direct effect and supremacy, national immigration controls could frustrate Treaty obligations.

The Maastricht Treaty changed the constitutional vocabulary by creating Union citizenship. Article 20 TFEU now provides that every person holding the nationality of a Member State is a citizen of the Union. Article 21 confers a right to move and reside freely, subject to limitations and conditions laid down in the Treaties and implementing measures. The phrase “subject to limitations and conditions” is crucial. Citizenship is constitutional, but not absolute. It was never a general right to unconditional residence and welfare in any Member State.

The Court’s early citizenship case law was ambitious. In Martínez Sala, a lawfully resident Union citizen could rely on non-discrimination. In Grzelczyk, a French student in Belgium could not be denied a minimum subsistence allowance solely because he was not Belgian where he was lawfully resident. In Baumbast, Article 21 was held capable of direct effect, subject to proportionate application of residence conditions. The Court’s famous formula that citizenship is destined to be the fundamental status of Member State nationals became the doctrinal emblem of this period.

The next phase was more complex. Directive 2004/38 codified and rationalised residence rights. It gives initial residence for up to three months with minimal formality, residence beyond three months for workers, self-employed persons, students and self-sufficient persons, and permanent residence after five years’ lawful residence. It also links equal treatment to lawful residence. This statutory framework gave Member States firmer grounds to resist welfare claims by economically inactive citizens who did not meet residence conditions.

The UK had a distinctive political relationship with free movement. For decades EU rights were domestically effective through the European Communities Act 1972. UK courts disapplied inconsistent national rules where required by EU law. Politically, however, free movement became associated with sovereignty, welfare, labour-market competition and border control. The European Union (Withdrawal) Act 2018 repealed the 1972 Act and retained or preserved certain EU-derived rights in domestic law, while the Immigration and Social Security Co-ordination (EU Withdrawal) Act 2020 ended the general EU free movement regime for the UK. For Durham students, the correct approach is chronological and constitutional: understand the EU law on its own terms before asking what remains domestically after Brexit.

The first principle is that the free movement of persons has both economic and citizenship dimensions. Economic movement remains the more secure route. A worker under Article 45 TFEU enjoys direct Treaty protection against nationality discrimination and unjustified restrictions. The concept of worker is autonomous and purposive. It does not depend on national employment classifications. The classic test asks whether the person performs services for and under the direction of another in return for remuneration. The activity must be genuine and effective, not purely marginal and ancillary. Part-time work, low pay and the need for public assistance do not necessarily defeat worker status. This prevents Member States from using formal classifications to hollow out Treaty rights.

The second principle is non-discrimination on grounds of nationality. Article 45 prohibits overt nationality discrimination in access to employment, remuneration and other conditions of work. Article 18 TFEU supplies a general non-discrimination principle within the scope of the Treaties, but is usually subsidiary: where a specific free movement provision applies, that provision should be used. Indirect discrimination also matters. A residence requirement, language requirement or qualification rule may disadvantage non-nationals even if neutral on its face. Such measures require justification and proportionality.

The third principle is restriction. In goods, Week 5 introduced the distinction between distinctly applicable measures, indistinctly applicable measures and market access restrictions. Persons law has similar but not identical logic. A national measure may breach free movement even without discrimination if it deters or impedes movement. Rules obstructing exit from the home State may also be caught, because free movement protects the right to leave as well as the right to enter. That said, the Court has often been more cautious in persons cases where the measure concerns social security, taxation, criminality, public policy or welfare eligibility.

The case law develops in three broad stages. The first concerns economically active movement. Van Duyn confirmed that EU law could bite directly on national decisions excluding an individual, while also recognising public-policy derogations. Levin established that worker status cannot be confined to full-time or subsistence-level work. The Court’s method is functional: if the person performs genuine and effective work for remuneration under direction, national labels are not decisive. This generosity served the internal market by preventing Member States from narrowing the personal scope of Article 45.

The second stage concerns citizenship’s expansion. Grzelczyk and Baumbast are the leading authorities. Grzelczyk used Union citizenship and non-discrimination to protect a lawfully resident student seeking temporary social assistance. Baumbast confirmed that Article 21 could confer a directly effective residence right, though subject to limitations and conditions. The Court’s method was constitutional: citizenship was not simply an appendage to worker status. It had independent legal force. Zhu and Chen extended the logic to family life in a striking way: an infant Union citizen with sufficient resources could rely on EU law, and her third-country national mother could derive residence rights necessary to make the child’s rights effective.

The third stage concerns consolidation and retrenchment. Metock protected the effectiveness of movement rights by rejecting a prior lawful residence requirement for third-country national family members of Union citizens. Zambrano then created the exceptional Article 20 “substance of rights” doctrine, protecting Union citizen children from being forced in practice to leave the Union. But the Court subsequently confined that doctrine. Dano, and the later line of social assistance cases, show that citizenship is not a general passport to unconditional welfare solidarity. Where economically inactive citizens do not satisfy Directive 2004/38 residence conditions, the host State may refuse certain benefits without breaching equal treatment.

The landmark cases should be used selectively in examinations. Do not cite Grzelczyk as if it decides every welfare case. Do not cite Zambrano as if it creates a general right for all third-country national parents of Union citizens. Do not cite Dano as if it abolishes Union citizenship. The correct technique is to place each case within the particular legal route: worker status, lawful residence, equal treatment, derivative family rights, Article 20 substance, or welfare limitation. That structure is usually what separates a competent answer from a high first-class answer.

See practice questions section below.

See further reading section below.