This chapter analyses the implications of the European Union's (EU) practice of negotiating megaregional trade agreements for democratic participation in general and the European Parliament (EP) in particular. It identifies avenues of legislative participation foreseen in international regulatory cooperation designs and centres on the Transatlantic Trade and Investment Partnership (TTIP) as the world's most advanced example of regulatory integration between some trading partners. The chapter presents the EP's approach to EU foreign trade in order to provide background for the discussion of TTIP and enable tracing the elements of this approach in the negotiating documents. It critically assesses the rationale for increased parliamentary involvement in the TTIP institutional machinery. The chapter offers policy recommendations as to the possible design of transnational cooperation between the EP and the US Congress as a way of addressing potential legitimacy shortfalls and bridging the gap between the citizens and transatlantic policy-making.