On March 26, 2021, the German Federal Constitutional Court (GCC) held that the Own Resources Resolution Ratification Act (ERatG) must not be executed by the Federal President for the time being. In its decision of 15 April 2021, the BVerfG rejected the application for a temporary injunction. The BVerfG found that the application in the main proceedings was neither inadmissible from the outset nor manifestly unfounded. However, the double balancing of consequences to be carried out in summary proceedings was to the detriment of the applicants. What is behind this, and what is to be thought of the questions of EU law and German constitutional law raised in this procedure? The article addresses whether the European Own Resources System and the Corona Reconstruction Fund conform with EU law and the German Basic Law. As will be shown in this Working Paper, the EU may have acted ultra vires (i.e., outside its authority) and may have violated Germany’s constitutional identity. The possibly insufficient legal basis of the Own Resources System and the possibly inadequate earmarking of the Corona Reconstruction Fund, as well as the high-liability risk for the member states, are problematic. If an ultra vires act or a violation of the constitutional identity were to exist, the GCC would, under its established case law and the German constitution, deny this EU program its effect in Germany and thus, in effect, finally stop the entire Corona Reconstruction Fund. This article will also present the possible procedural scenarios in the main action and the interaction of the ECJ and the GCC in the European constitutional court network.