The author presents the situation of legal relations that took place in the period 2015-2023 between Poland and the European Union (EU). The reform of the justice system organized by the ruling party was appealed by the European Commission to the Court of Justice of the EU. The CJEU analyzed and assessed the following fundamental legal issues: failure to fulfill obligations by a Member State, the rule of law, the system of disciplinary liability of judges, judicial independence, effective legal protection in areas covered by EU law, recognition of the content of judicial decisions as disciplinary offenses, compliance with reasonable deadlines, respect for the rights of judges to defense in disciplinary proceedings, the right and obligation of national courts to refer requests to the CJEU for a preliminary ruling. It ruled that the Republic of Poland (RP) had failed to fulfill its obligations towards the European Union (EU). This study concerns case law. The situation created during this period resulted in a significant weakening of the protection of the value of the rule of law within the meaning of the extensive case law of the CJEU presented in this article. According to this body, the Republic of Poland has failed to fulfill the obligations set out in the EU treaties.