The subsidiarity principle and national parliaments role : from formal need to real use of powers

Subsidiarity constitutes a guiding principle of the EU exercising power and the idea of involving national parliaments in the EU legislative procedure was seen as the best solution to increase democracy and transparency of the EU decision-making process at the European Convention established in 2001. Such a mechanism enables national parliaments to ensure the correct application of the principle of subsidiarity by the institutions taking part in the legislative process. This article examines how this principle is implemented by the national parliaments and EU responsible institutions. What is the novelty derived from the Treaty of Lisbon? Do national parliaments participate actively in the implementation of subsidiarity? If yes, what are the tools at their disposal? To answer all of these questions we try to shape a framework for understanding the phenomenon.