The Liberal Intergovernmental theory is one of the most important integration theories explaining the creation and development of the European Union. Andrew Moravcsik developed this theory, which perceived the integration as an outcome of international bargaining, whereas the governments played the key role. The national governments associated with it have a clear and specific point of view about their preferences and pursue these preferences in bargaining with other member states so that this bargaining is in accordance with becoming more powerful and with greater competence. It is therefore relevant to explain why these member states decided to strengthen the European Parliament (EP), and what their interests are in making the European Parliament, a supranational institution, as... powerful as the Council. Hence the question which arises here: To what extent can the Liberal Intergovernmentalism explain the strengthening role of the European Parliament after the Lisbon Treaty?