(en) Within the context of the European democratic and economic crisis in the thirties, this thesis, by means of the indirect use of an electoral article, analyses some behaviour similarities of two ideological opposing parties. One of them is a right wing party led by Leon Degrelle and the other one is a left wing one whose leaders are Emile Vandervelde, Paul-Henri Spaak and Henri De Man. The functioning of both parties, the balance of power governing them and their impacts on the preservation of democracy are explained.