The accession of up to twelve East-European States to the European Union in the next decade is likely to change the possibilities for substantive consensus within the Union for the worse. Yet, the consensus on the means to pursue the objectives of the Union has thus far made European integration successful. Insofar as the feasibility of substantial consent between the Member States diminishes, the need to have rules and principles regulating the conflict between the relevant actors increases. These rules and principles must facilitate the creation of solutions to the new challenges that face the Union. Thus, it is essential for the Union's future that the law of the European Union offers both such rules and principles. One of the most outstanding principles which could perform this important task is the principle of loyalty as developed by the European Court of Justice (ECJ) based on Article 10 EC Treaty.