Shopping for a better deal? Party switching among grassroots members in Britain

People who join political parties are motivated primarily, although not exclusively, by ideological impulses. So, given the often considerable ideological differences between parties, one might presume that very few those who later leave one party would be keen to join another. However, using a comprehensive 2019 survey of British party members, we not only identify several factors associated with switching parties (being especially socially liberal or socially authoritarian; being a Brexiteer; being a campaign activist; working in non-manual occupation; having a university degree; being a man rather than a woman; being older rather than younger; and being a current member of one of the country’s smaller political parties), but we also show, first, the flows between parties and, second, that party switching at the grassroots is far more common than many imagine. Even so, and notwithstanding the fact that switching impacts on different parties in different ways, it is not sufficient to support oft-voiced claims of widespread entryism into either of Britain’s two main parties – at least on the sort of scale that might account for Labour’s shift to the liberal-left or the Conservatives’ shift to supporting a hard Brexit.