Party survival is an important component of parliamentary democracy that enables stability of the political system and policy implementation. The disappearance of a certain party from parliament may leave some social groups without sufficient political representation and decrease electoral alternatives (Zur 2019). At the same time, electoral volatility is quite a common phenomenon, especially across the new democracies (Mainwaring & Torcal 2006; Cyr 2016). Approximately 70 percent of political parties that emerged since 1945 failed to keep their seats in parliament (Zur 2019: 960). Unstable political systems of Central and Eastern Europe (CEE) create additional risks for party survival. The region is characterized by high levels of electoral volatility that appear when voting is switching dramatically from one election to the other (Cyr 2016). The disappointed voters could easily change their party preferences in the following elections, especially in the context of the absence of a strong mainstream party, which puts all parties at risk of disappearing (Tavits 2006; Dalton & Weldon 2007; Zur 2019).
Cohesion of political parties is one of the important factors determining parties’ survival as well as their chances of impacting public policy (Andeweg, Thomassen 2010), gathering supporters and resources and achieving durability and resistance to internal and external shocks (Harmel et al. 2018). The level of legislative party cohesiveness in parliamentary systems impacts on governments’ ability to endure (Saafeld 2009), influences parties coalition behavior (Pedersen 2010) and ensure smoothness of a legislative process. For the opposition parties, it allows for the efficient control of the government. However, there are several cross-pressures regarding the submission of individual MPs to the party line, including contradictory expectations from represented electoral constituencies or their plans of obtaining public offices in the future. The party can reduce this tension by allowing MPs to express their positions in the debate, at the same time obliging them to cooperate in legislative voting. Therefore, we hypothesize that the parties demonstrating a medium level of coherence in debates and high coherence in legislative voting will have a lower risk of internal splits and higher chances of survival. In order to test this hypothesis, we analyse parliamentary speeches and data on legislative voting of political parties in CEE region.