Parliaments are not generally conceived of as leaders. However, the European Parliament (EP) has played a pivotal leadership role in transforming the character of representative democracy at EU level. For much of its history the EP argued for a representative system based on competition between institutions operating on the principle of a separation of powers. However, following the Lisbon Treaty and the 2014 European elections, a rather different paradigm has grown in prominence, namely an embryonic form of parliamentary government where executive power is channelled through the elected representatives of the people. The Parliament has thereby been at the centre of a transformative development in the structures of representation of the EU. The precise consequences of this change remain uncertain but it is likely to prove difficult to reverse the 2014 institutional revolution, with its profound implications for the debate about the character of representative government at EU level.