Czech Constitutional Court and EU law: from sugar quotas to pensions

The Czech Constitutional Court sits in Brno, far from the theatre of Prague and from the institutions in Luxembourg and Brussels, and it chooses its words with care. Since Czechia joined the EU it has faced the same question again and again: where does the authority of EU law end and the authority of the Czech constitution begin? Its answers have a consistent tone. Yes to membership, yes to the primacy of EU law in everyday practice, and a reserved, rarely used right to say no if something fundamental is at stake.

This explainer follows the main decisions in order. For the general theory, see EU law supremacy and national courts; for how directives and regulations reach Czech law, EU regulations versus directives; and for the court itself, the Czech Constitutional Court explained.

The constitutional basis

The Czech Constitution dates from 1992, when EU membership was not yet a serious prospect, and it had to be amended to make accession possible. A constitutional amendment of 2001 introduced Article 10a, which allows certain powers of Czech bodies to be transferred to an international organisation or institution by international treaty. Ratification needs the consent of Parliament, unless a constitutional act requires a referendum instead, as it did for EU accession in June 2003.

The Constitutional Court is the guardian of the constitutional order, with fifteen judges appointed by the President with the consent of the Senate, each for a ten-year term. It can review laws for conformity with the constitutional order, and it decides complaints by individuals whose constitutional rights have been violated. For the treaties, the Constitution also gives it a preventive role: it can review an international treaty before ratification, at the request of bodies that include the Senate and the President, as happened with the Treaty of Lisbon. The institutional picture is covered in our piece on the Czech constitution in plain terms.

Sugar Quotas: a first position (2006)

The first major ruling came in March 2006, in the case known as Sugar Quotas III (Pl. ÚS 50/04). It concerned a Czech government decree implementing the EU sugar regime, challenged on the ground that the underlying EU rules violated Czech constitutional rights. The Court rejected the challenge, but set out a framework while doing so.

It held that EU membership was an exercise of the transfer of powers the Constitution allows, so EU law was not a foreign body in the Czech legal system. In principle, it said, it would not examine EU legislation against the Czech constitutional order, because as long as the EU protects fundamental rights comparably to the Czech standard, review at national level is unnecessary. The reasoning resembles the German Solange II approach. The Court reserved its position for two narrow cases: if the EU acted in a way that threatened the essential attributes of a democratic state governed by the rule of law, or if there were a breach of the very substance of fundamental rights.

Lisbon: two rulings (2008 and 2009)

The Treaty of Lisbon, which entered into force on 1 December 2009, needed ratification in all member states. In Czechia the Senate asked the Constitutional Court to review it in advance.

In November 2008, in Lisbon I, the Court examined the parts of the treaty the Senate had referred and found them compatible with the constitutional order. It dealt in detail with the transfer of powers, the flexibility clauses, the Charter and the treaty's revision mechanisms, and concluded that the Czech Republic remained a sovereign state.

In November 2009, in Lisbon II, after a second request, it found the treaty as a whole compatible, removing the last obstacle to ratification. President Václav Klaus had held back until the Court ruled and until the other member states agreed that the Charter of Fundamental Rights would apply differently to the Czech Republic (a deal reached in the European Council in October 2009). He signed the instrument of ratification on 3 November 2009, the day of the Court's ruling.

Slovak Pensions: the confrontation (2012)

The most dramatic decision involved a pension. After Czechoslovakia split in 1993, a bilateral agreement dealt with the pensions of people who had worked in the former federation: periods worked on the other state's territory were paid by that state. A Czech pensioner, Ms Landtová, had worked in the Slovak part of Czechoslovakia before 1993. She argued that the arrangement left her with a lower pension than if the same work had been done on Czech territory.

The question went to the Court of Justice. In Landtová (case C-399/09), decided in 2011, the Court held that EU social security coordination rules prevented the Czech authorities from applying the arrangement in a way that disadvantaged her.

The Czech Constitutional Court was then asked to rule, and in its judgment of 31 January 2012 (Pl. ÚS 5/12) it held that the Court of Justice's judgment was ultra vires, issued outside the powers conferred on the EU. Its reasoning was that the Court of Justice had interpreted EU social security law in a way that effectively reopened an arrangement between the Czech and Slovak states that predated Czech accession, and that the EU had no competence to do that. The Czech court would not apply the judgment. A national court had not, to our knowledge, taken such a step before, and the ruling is widely described as the first of its kind.

It drew considerable attention, as both a landmark and an exception. In later decisions the Court has stressed that ultra vires review is for exceptional cases, and Czech courts have gone on applying EU law in the ordinary way. The question of Czechoslovak-era pensions remained a subject of cross-border political discussion; we touch on it in Czech-Slovak relations after 1993.

How the court deals with EU law in daily practice

Outside the headline cases the Constitutional Court's treatment of EU law is routine. It regards EU law as part of the legal environment ordinary courts must apply, and it reviews whether they ignored it in a way that violates the right to a fair trial. A court that brushes aside an EU law argument, or declines without reasons to make a preliminary reference to the Court of Justice where it was required to, may be criticised for arbitrariness. The Constitutional Court itself has not, as far as is known, referred a preliminary question to the Court of Justice, unlike some other constitutional courts (as of 2026; check the Court of Justice's statistics for current data).

What this means in practice

For residents and businesses the conclusion is reassuring and a little dull. Czech courts apply EU law as a matter of course, the Constitutional Court accepts primacy within limits, and it has used its reserve power only once in a way that drew international attention. The cases still discussed show a relationship built on dialogue between courts, not automatic deference in either direction.

For lawyers, compliance staff and public-affairs people, the useful habit is to read the Constitutional Court's reasoning on EU law next to the Court of Justice's case law. Each explains the other.

Frequently asked questions

Where does the Czech Constitution allow EU membership?

Article 10a, added by a constitutional amendment in 2001, allows certain powers to be transferred to an international organisation by treaty.

What was the Slovak Pensions ruling?

A January 2012 decision in which the Constitutional Court held that a Court of Justice judgment in the Landtová case exceeded the EU's powers.

Did the Court block the Lisbon Treaty?

No. In 2008 and 2009 it found the treaty compatible with the Czech constitutional order.

How many judges does the Court have?

Fifteen, appointed by the President with the consent of the Senate for ten-year terms.