It is suggested in this paper that the Court of Justice has made a modest, although by no means a trivial, move towards becoming the Constitutional Court of Europe, particularly in the N.S. case, where it rejected the Union's guiding rule of automatic reliance on the principle of mutual confidence. The paper proposes that this represents a test, labelledthe "horizontal Solange" test and which is composed of two tiers. The first, substantive, tier forms the Solange component. Cooperation between Member States will be maintained as long as all the Member States systematically adhere to core European fundamental rights. If the evidence shows that a systemic violation of core European fundamental rights took place in a Member State, other Member States should suspend their cooperation. The second, institutional, tier forms the "horizontal" component. The national courts are entrusted with the task of reviewing whether the other Member States abide by the European standard of protection of fundamental rights.The exact substantive contours of the test are examined alongside the test's possible implications for related fields of law of the European legal order. The test also allows the ECJ to interweave the different European fundamental rights systems into a fully integrated judicial dialogical network, and to steer the exact direction in which European legislation should advance.
Common Market Law Review