Conscientious objection has achieved a particular place in contemporary law and culture. Lawyers, political theorists, ethicists, health professionals and others have debated how we best negotiate the tensions that can exist between professional obligations and private beliefs. Conscientious objection to abortion care has been a particular focus of these discussions. In this article, we draw on theoretical work on ‘jurisdiction’ to provide an account of what is embedded in claims to conscience and what the effects of such claims are. We focus specifically on refusals of abortion care enabled by section 4 of the Abortion Act 1967. We argue that legitimating narratives on conscience seek to achieve seemingly contradictory goals: entrenching abortion as morally ambiguous while securing it as part of medicine’s monopolistic practice. While section 4 provides the focus, our concerns extend to the wider landscape and impact of claims to conscience. Through our jurisdictional analysis, we seek to better understand such claims and dramatically reorient thinking by grounding the conscience clause squarely in the politics of ‘task areas’, professional domains, market control and claims of epistemological authority.