The principle of non-regression is an novel concept in the EU rule of law area. The Court of Justice of the European Union ("Court" or "CJEU") has recently discussed it e.g., in Repubblika (Maltese Judges), Commission versus Poland (Disciplinary régime applicable to judges), Advocate General  Tanchev in his Opinion in A.K. v. KRS (Independence of the disciplinary chamber of the Supreme Court). This paper examines the non-regression principle with a focus on the rule of law and judicial independence in the EU not least because it is understudied. Its potential is underestimated for expanding the reasoning of the CJEU, and the Commission as regards their approach to addressing the sustained attacks on judicial independence in the two Central and Eastern European countris of Poland and Hungary, but also increasingly, judging from the rising number of judicial independence and rule of law cases, in Romania. Maltese Judges is the first ruling of the Court in which the principle of non-regression appeared. In this landmark judgement, acording to Leloup, Kochenov, and Dimitrovs, the Court asserted "an entirely new "non-regression" principle in EU law based on the connection between Arts. 49 and 2 TEU, (...) and addressed a well-known lacuna undermining the EU legal order". In light of that ruling, it is useful to set subsequent research questions: What is the substance and scope of the principle of non-regression in the rule of law and in relation to judicial independence in the EU, and what are the recent trends in the Court´s case law whereby this principle has been invoked to address the rule of law backsliding in the Member States? Can we discern the benchmarks, in the form of substantive standards and in terms of time, against which regression is measured? Considering that, until now, the principle of non-regression has been employed principally with regard to judicial independence, could we apply the concept with respect to other EU values such as democracy, or fundamental rights?