This article examines the impact of reforms on the outcome of Labour party leadership contests since the premiership of Tony Blair. From a theoretical perspective, these reforms are characterised by a tension between a general trend towards increasing “democratisation” of political parties and the power interests of intra-party actors. While there have been significant changes to both the nomination stage and the final ballot, the impact of these changes has to be strongly qualified. Instead of a major “democratisation” through targeted and deliberate reform measures, simple shifts in the power structure between strategic actors are more prominent among reform effects. Meanwhile, the trend towards “democratisation” in relation to the final ballot stage was largely driven by the massive membership surge since 2015, as well as low-key reform measures unconnected to handing ordinary party members more influence over the election process.