This publication focuses on the characterization of the Slovak party system and its analysis from the perspective of cleavages and emerging government groups. The monograph also includes a description of the individual types of emerging government coalitions and their politological analysis on the basis of the RILE index (right-left positioning). The said index is used to specify the programmatic differences of the emerging coalition governments and the impact of the development of the party system in Slovakia on their nature in the period from 1990 to 2012. The work is focused on the development trends of the Slovak party system on the background of programmatic heterogeneity of the individual coalition groups and the overall development of the variable tensions in the party system. The categorization of the government groups is based on the positional and programmatic orientation of the parties, which was published in the framework of the international database CMP (Comparative Manifestos Project). The Wissenschaftszentrum Berlin für Sozialforschung (WZB) database processes, inter alia, the data relating to the political programs of the parties within the framework of their comprehensive ideological orientation. The Center for Social Research in Berlin thus contains relevant internationally acceptable comparisons of the party systems and their development. The aim of this publication is to characterize the format and type of the party system in Slovakia, its consolidation and the resulting operational problems between the election system and party system. The aim is also to extend the analysis of the Slovak party system to the specification of positional values and programmatic orientation of the parties in Slovakia based on the internationally accepted database and the RILE criteria. The publication also contains the tables with data on the proximity of variable tensions in the party system after each parliamentary elections and the relevant quantification on the RILE scale. The RILE scale will help us assess the programmatic heterogeneity of the government coalitions also in view of the political discourse on this issue. The work will also verify the hypothesis that the programmatic convergence of the parties in the left-right spectrum creates space for the emergence and establishment of extremist and antisystemic parties in the parliamentary establishment.