The European Commission President Ursula von der Leyen has described a recent ruling by a Polish court as “a direct challenge to the unity of the European legal order”.

Earlier this month, Poland’s Constitutional Tribunal ruled that parts of EU treaties were incompatible with the Polish Constitution.

Von der Leyen told the European Parliament that the EU could not, and would not, allow its common values to be put at risk. “The commission will act,” she said.

Responding, Polish prime minister Mateusz Morawiecki accused the EU of blackmail. He said that he rejected "the language of threats", and accused the EU of overstepping its powers.

Judicial independence ‘undermined’

Referring to long-standing EU concerns about the independence of the judiciary in Poland, the commission president said that the situation had now worsened.

“This is the first time ever that a court of a member state finds that the EU treaties are incompatible with the national constitution,” she said.

Von der Leyen argued that the ruling undermined the protection of judicial independence, as guaranteed by the Treaty of the European Union, and as interpreted by the European Court of Justice.

“Without independent courts, people have less protection, and consequently their rights are at stake.” she told MEPs.

Three options

The commission president also set out a number of measures that the EU body could take in response to the Polish judgment.

She said that the first option was a legal challenge to the judgement, while the commission could also look at imposing conditions on the distribution of €2.1 billion that it planned to invest in Poland in the coming years.

The third option, von der Leyen concluded, was the article 7 procedure, which she described as a “powerful tool” in the EU treaty. This article provides for sanctions against countries, where they do not respect the EU’s common values – including the rule of law.