A lack of party unity can have a significant negative effect on the electoral success of European parties.

How important is intra-party unity to election outcomes? Michael Clark provides an overview of the effect that in-fighting and public disagreements can have on a party’s vote share. He notes that a lack of unity is likely to be more damaging when it involves high profile party members, rather than backbenchers, and when clashes are over key policy areas which are electorally salient.