A ‘Virtual Third Chamber’ for the European Union? National Parliaments after the Treaty of Lisbon

The Treaty of Lisbon introduces an early warning mechanism (EWM) which empowers national parliaments to intervene directly at the EU level; they may now raise objections to – and even play a role in blocking – EU legislation. The EWM represents a new model of parliamentary involvement in international relations: national parliaments now constitute a virtual third chamber for the EU. Though they do not meet together in the same physical space, national parliaments collectively form a body that can, at least to some degree, perform three key parliamentary functions – legislation, representation, and deliberation. First, it gives national parliaments the power to influence legislative outcomes at the EU level. Second, it provides a new channel of representation linking the citizen with the EU. Third, it creates a new forum for debating the substantive merits of proposed EU legislation, particularly regarding its compliance with the principle of subsidiarity.