The impact of the procedural constraints in legislatures has been generally neglected. Nonetheless procedural constraints are able to generate opportunity structures and may enhance the weight of parliamentary parties in the overall party organisations, on one hand, and increase the government capacity in the parliamentary arena vis à vis the opposition, on the other hand. The legislature structure may facilitate the centralisation of the legislative process, acting as a further causal factor in the identification of the parties with the government and opposition roles. It will referred to this identification as the process of institutionalisation of the government-opposition relation. As a consequence of the variable arrangements of procedural constraints and legislature structures, there are cases in which the government dominates the legislature and cases in which it undergoes major parliamentary control. Hinging on these perspectives of research, the paper focuses on the institutionalization of the government-opposition relation in some Eastern European democracies.
