With the acceptance of the European Constitution, decision procedures will be modified and the division of authority among its institutions will be altered. The new rules that guide the decision procedure in the European Union will be given by Art. III-396 of the European Constitution. By comparing article III-396 of the European Constitution with the most frequently used Art. 251 ECT of the treaty of the European Community, we will be able to discover significant differences that the European Constitution brings to the decision procedure. Using the exact same method as Kolmar applied on Art. 250-252 of the Treaty of Amsterdam in "An Analysis of Institutional Change in the European Union" (2003) we have been able to attain information on what are the decisive actors in the different decision procedures, how the tendencies for dentralization are inherent in the different decision procedures and what each decision procedure's ability is to guarantee conflict minimizing compromises between the institutional actors. We show that when the European Parliament has few possibilities to amend, both the European Parliament as the European Commission has less real authority under Art. III-396 of the European Constitution, and that the role of "most decisive institutional actor" shifts from the European Parliament to the Council of Ministers. When the European Parliament has more possibilities to amend, we detect a difference in the equilibrium of the decision procedure, but no difference in the dynamics of the decision procedure.