Party switching by members of Parliament is a common phenomenon in democracies. Despite several empirical investigations of this phenomenon, party switching has not yet been investigated from a moral point of view. This article aims to fill this gap. By analyzing party switching from the point of view of relational egalitarianism, the article argues that party switching may be wrong because (i) the politician thereby acts on selfish interests which should be excluded from their decision-making as a representative; (ii) the politician thereby treats their constituents and/or party members paternalistically; and (iii) it expresses relational inequality between the member of Parliament and their voters or between the member of Parliament and their party members. There are instances, however, in which party switching is not wrong, and the last part of the article discusses what this means for whether party switching should be prohibited.