L’arbitro dell’unitarietà e della differenziazione: il sindacato di costituzionalità sulla Erforderlichkeitsklausel alla luce del novellato art. 93 GG

The paper analyses the new type of judicial review on concurrent legislative power exercised by the Federation, as introduced by the recent constitutional reform, which amended art. 93, para. 2 of German Basis Law. The paper begins by examining the role of Bundesverfassungsgerciht (the German Federal Constitutional Court) as a guardian of the principle of unity, underlining the steps that were carried out in order to consolidate judicial review on concurrent legislative power exercised by the Federation. Analysis concentrates on the new function assigned to the Bundesverfassungsgericht by the amended art. 93, c. 2 GG. This function can be added to the so-called "necessity-clause" which gives the Bundesverfassungsgericht the power to review federal law when parliamentary or political procedures have proved to be unsuccessful. Finally the paper examines the arbitration function of the Bundesverfassungsgericht in the context of the German legal system.