The paper assesses how would the composition of the winning/losing coalitions in the EC Council change after the decision-making rule of the Lisbon Treaty comes in force. The paper is built on the empirical data on voting and statements of the member states after two waves of eastern enlargement. Assuming that the distribution of preferences of member states of the EU remains largely stable and the number of member states does not change, I develop spatial models that depict the political spaces occupied by coalitions of member states in various agendas of the EU legislative process from 2004 to 2010. These models are subsequently tested against the simulated coalitions rendered by the application of the new decision-making rule of the Lisbon Treaty. Policy spaces are compared both in terms of size and direction of the shift and in terms of membership of the winning/losing coalitions.
