The Treaty of Lisbon introduces an early warning mechanism (EWM) which empowers national parliaments to intervene collectively at the EU-level; they may now raise objections to – and even play a role in blocking – EU legislative proposals. 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 merits of proposed EU legislation, which will increase the salience of national parliaments’ concerns, particularly with respect to subsidiarity.
