Fiscal Sovereignty as Part of the Constitutional Identity of Member States

The central legal issue explored in this paper is whether constitutional courts can oversee the implementation of European Union (`EU`) legislation through an identity control mechanism. First, the paper will examine the evolution of fiscal sovereignty in the context of globalization. Second, it will assess how constitutional courts have progressively judicialized the concept of constitutional identity, transforming it into a legal tool for challenging EU law. Finally, the study will explore whether the constitutional identity control mechanism can serve as a means of reconciling two opposing concerns: the democratic deficit in EU fiscal governance and the potential for national courts to abuse constitutional identity as a means of resisting European legal integration. A critical issue that emerges is whether EU law itself, particularly in the field of direct taxation, promotes values that align with the constitutional identity of the EU, such as tax fairness or the principle of solidarity. If this is the case, can national constitutional identity claims justifiably prevail, or should the EU’s overarching constitutional framework take precedence?