Abstract: The regime of parliamentary democracy, widely used all over the world nowadays, has been able to spread into so many state structures due to its unique constitutional quality of eff ective division of power. Its importance has, in the past century, come to a permeation with the international law structure and has certainly affected the principles of international organisations’ existence as well. The aim of this paper is to analyse the question of power division within the European Union with a closer look at the fundamental EU institutions and their standing in the current treaty base. The contribution comes to the conclusion that the state model of public authority is able to be pursued into the supranational organisation structure, just in its simpler, overlapped and incomplete form, due to the character of the surveyed sample of such an organisation. The fundamental EU institutions are not just being close to represent the public authority, they are also subject to the division of its power (including the non-well or partly-set elements of power division) and principles of constitutional checks and balances (with its overlapping competences character).

Keywords: Representative democracy, state division of power, international organisations attributive competences, EU as a sui generis, EU  institutions, the Treaty of Lisbon