The reasoned proposal submitted on 20 December 2017 to the Council by the European Commission on the rule of law in Poland is the fi rst to launch a procedure for the protection of European Union’s (EU) values. It was preceded by two-year activities of the European Commission aimed at establishing a dialogue between the Polish government and the EU regarding the basic problems, such as judicial independence and independent constitutional control. The purpose of the article is to present the EU’s legal framework whose goal is to strengthen the rule of law. Measures taken by the European Commission must be analysed from the perspective of the treaty framework and international legal obligations of the EU member states. The current political discourse often has a legal background. The study is based on the analysis of legal documents.