At this session Jan Komárek will present his article (forthcoming in European Law Review), which advocates limitation of lower courts power to send preliminary references. It shows that many arguments against this are not sufficiently thought out and are used rather mechanically. It proposes the following: 1. Limiting preliminary ruling procedure to courts of last instance as a rule; 2. As a necessary exception to 1, when a lower court considers that one or more arguments for invalidity, put forward by the parties or as the case may be raised by it of its own motion, are well founded, it must stay proceedings and make a reference to the Court for a preliminary ruling on the acts validity; 3. As a possible exception to 1, the Council can decide which EU law measures may be subject to preliminary references from lower courts. The proposal sees national judicial hierarchy as an important element of the Union judicial process, which can make the preliminary ruling procedure rational and effective, while keeping its original purpose. At the same time it suggests some measures that strike the balance between judicial protection of individuals and effectiveness. The key idea behind the proposal is the need for more trust in national courts, if they are to be truly considered as Union courts.