The Boiling Point. Three Lessons From Party-Switching in the Brexit Era

In this article, the author demonstrates how the phenomenon of party-switching can be used to shed light on and analyse the challenges arising from Brexit at the parliamentary level, and argues that it acts as an external shock, leading to a so-called “boiling point” scenario whereby fundamental bonds of the parliamentary system, namely, long-standing party affiliations, rapidly disintegrate. The dynamics of 271 instances of party-switching in the House of Commons from 1992 to 2023 are presented, with a particular focus on the short period between February and October 2019, during which there was a surge of 89 such cases. Adopting a perspective focused on party affiliation changes, the author argues that the British case allows us to carefully formulate three general conclusions: 1) Every parliamentary system has a potential boiling point; 2) The systemic boiling point has an emergent character; 3) It does not imply a formal power shift in the Government.