opening clauses are relevant to the constellation at hand or that they contradict the objective of the regulation, overriding the fully harmonised level of substantive data protection that the GDPR seeks to ensure. b) Regarding the application of legal provisions that are fully harmonised under EU law, the relevant standard of review does not derive from German fundamental rights, but solely from EU fundamental rights; this follows from the precedence of application of EU law (see aa) below). The possibilities of review reserved by the Federal Constitutional Court in the event of a general erosion of such protection remain unaffected (see bb) below). 42 aa) It is in line with established case-law that German fundamental rights are not applicable in a review concerning the validity of legislation fully harmonised under EU law (cf. BVerfGE 73, 339 <387>; 102, 147 <162 et seq.>; 118, 79 <95 et seq.>; 121, 1 <15>; 123, 267 <335>; 125, 260 <306 and 307>; 129, 78 <103>; 129, 186 <199>). The same holds true for the application of legislation specifying such EU law. 43 The application of EU fundamental rights as the standard of review follows from the transfer of sovereign powers to the European Union under Art. 23(1) second sentence GG. Where the EU enacts legislation that is applicable, and must be applied uniformly, throughout the EU, it follows that the fundamental rights protection afforded in this context must be based on uniform standards, too. The Charter of Fundamental Rights of the European Union guarantees such protection of fundamental rights. In such a case, German fundamental rights are not applicable as this would run counter to the objective of harmonisation of the law. While the fundamental rights of the Basic Law can, as a rule, simultaneously ensure the level of protection of the Charter in areas allowing for fundamental rights diversity that are not fully harmonised (cf. BVerfG, Order of the First Senate also issued today - 1 BvR 16/13 -, paras. 50 et seq., 55 et seq.), in respect of fully harmonised EU legislation, it cannot be assumed that the Basic Law simultaneously ensures such a level of protection. Here, EU law in fact requires that the law be applied uniformly. This prevents, from the outset, Member States from applying their domestic fundamental rights standards because the application of these standards would lead to divergences in the application of fully harmonised legislation. At present, it cannot be assumed that there are fundamental rights standards in the EU that are congruent beyond the common foundation of the European Convention on Human Rights (ECHR), which consolidates different fundamental rights traditions, but does not seek uniformity. It must be noted that the Charter interacts with very diverse legal orders, which also have differing approaches with regard to fundamental rights protection. Such differences already manifest in the external form and the institutional integration of fundamental rights protection. They are also evident in the requirements for restricting fundamental rights as regards the weighing of public interests or the resolving of conflicting value decisions enshrined in different fundamental rights. Finally, they can also be found in the basic principles setting out to what extent and with what intensity judicial review on the basis of fundamental rights is permissible or required. These differences in domestic fundamen- 44 8/36