The ECJ established the supremacy of EU law over conflicting national law, holding that member states cannot unilaterally override EU obligations through subsequent domestic legislation.

This landmark case established that UK courts can disapply Acts of Parliament that conflict with EU law and can grant interim relief against the Crown. It fundamentally changed the relationship between EU law and domestic law in the UK.

Two joined cases establishing state liability for breaches of EU law. German beer purity laws prevented French beer imports; UK fishing legislation breached EU law. ECJ held Member States liable in damages where breach is sufficiently serious and causes direct loss to individuals.

The ECJ upheld the European Stability Mechanism (ESM) treaty, confirming member states' competence to establish stability mechanisms outside EU law. The case addressed the relationship between EU law and emergency financial measures during the eurozone crisis.

EU law supremacy requires domestic courts to disapply conflicting national legislation.

Foster was employed by British Gas and sought to rely on EU Directive 76/207 on equal treatment. The CJEU held that unimplemented directives can be enforced against bodies that are under state control, provide public services under state authority, and have special powers beyond normal law.

The ECJ established the doctrine of direct effect, holding that EU law creates individual rights that national courts must protect, fundamentally transforming the relationship between EU and national law.

ECJ cases developing the Francovich state liability doctrine, establishing that member states are liable for legislative and administrative breaches of EU law where the breach is sufficiently serious and manifestly disregards EU law limits.

Omega, a German company, was prohibited from operating laser games simulating homicidal acts. The restriction was challenged as contrary to free movement of services, as the laser equipment was imported from the UK. The ECJ held that protecting human dignity could justify restricting free movement, even where the concept was not uniformly understood across the EU.

Helen Marshall was dismissed by Southampton Health Authority at age 62, while men could work until 65. She claimed this breached the Equal Treatment Directive 76/207/EEC. The ECJ held that EU directives can be directly enforced against State bodies (vertical effect) but not private employers (horizontal effect).

The ECJ established that EU directives can have direct effect against member states, and that personal conduct restrictions on free movement must be based on present threats, not mere membership of organizations.

An Italian lawyer challenged the nationalisation of the electricity industry, arguing Italian law conflicted with the EEC Treaty. The ECJ held that EU law creates a separate legal order that takes precedence over national law. Member States have limited their sovereign rights by creating a body of law binding on both nationals and themselves.

Right to paid annual leave accrues immediately without qualifying employment periods.

Ratification of Maastricht Treaty a non-justiciable matter of high policy.

Certain statutes have constitutional status and cannot be impliedly repealed.

Austrian authorities allowed environmental protestors to block the Brenner motorway for 30 hours, disrupting trade. The ECJ held that the blocking of a major transit route could be justified where it balanced free movement of goods against fundamental rights to freedom of expression and assembly, provided the restriction was proportionate.

Courts cannot invalidate Acts of Parliament regardless of international law breaches.

ECJ established multi-factor test for identifying business transfers under EU law.

House of Lords rules prerogative powers subject to judicial review

Statutory schemes override prerogative powers in the same field.