AbstractCentralized agenda control is a feature of many parliaments, with important consequences for the conduct and outcomes of legislative politics. Much previous work has thus sought to understand the emergence of centralized agenda‐setting rules. We extend this literature by studying the “Balfour reforms”, which centralized agenda control in the early twentieth century UK House of Commons. Our aim is to probe a conventional claim in the existing literature: that the opposition supported these reforms. This is a counter‐intuitive claim, which rests on relatively little direct evidence. We analyze historical roll‐call data from 1902 to assess how far the opposition supported agenda centralization. We complement this analysis by examining attempted amendments and speech contributions to parliamentary debates. Contrary to the standard view, we find that the primary opposition party consistently resisted these reforms. This evidence of controversy rather than consensus revises our understanding of a key milestone in the development of the Westminster parliament, and contributes to the wider literature on the choice of agenda‐setting procedures.