This thesis aims at studying the development of the party cohesion and oligarchichaltendencies in the party groups of the Swedish national parliament, riksdagen, after theintroduction of two clear block coalitions during the years 2006-2010.The result of the cohesion during these years has been compared towards the years 1998-2006.The research method being used has been 18 semi structured interviews with member of the parliament during the examined years. The main findings show an increment of both the cohesion and the oligarchical tendencies after the block coalitions during the years 2006-2010. The result verified therefore also the two originally stated hypothesis..

This thesis aims at studying the development of the party cohesion in the Swedish national parliament, riksdagen, after the introduction of preference voting in the election of 1998. The party cohesion has been measured during parliamentary sessions before and after the reform. The result of the cohesion during each of the sessions has then been compared towards each other. The cohesion was measured between the members of parliament viewed as a whole, and within the party groups during the different sessions. The research method being used has been a quantified statistical voting analysis, making the comparisons of party cohesion during the different parliamentary sessions as easy as possible.