Most scholars conclude that the introduction of one member, one vote (OMOV) into the electoral college that chooses the Labour leader demonstrates a new, reduced role for the party's affiliated trade unions. This article examines the adoption of OMOV by Labour. It looks at discussions in the Labour party–trade union review group that moulded the decision to adopt OMOV during 1992–1993. Drawing on the full breakdown of results, it goes on to examine the outcome of the 1994 leadership contest. The distribution of votes, union by union, indicates that, contrary to the conventional view, trade union leaderships retained the capacity to shape the pattern of voting through their ability to nominate candidates. The article concludes that the introduction of OMOV did not reduce the role of trade union leaderships in Labour's internal affairs in the manner that many scholars have concluded to be the case.