In politics, a cartel party or cartel political party is a party which uses the resources of the state to maintain its position within the political system. Katz and Mair argue that "parties in Western Europe have adapted themselves to declining levels of participation and involvement in party activities by not only turning to resources provided by the state but by doing so in a collusive manner".
The concept of the cartel party was first proposed in 1992 as a means of drawing attention to the patterns of inter-party collusion or cooperation rather than competition; and as a way of emphasising the influence of the state on party development. In definitional terms, the cartel party is a type of party that emerges in advanced democratic polities and that is characterised by the interpenetration of party and state and by a pattern of inter-party collusion. With the development of the cartel party, the goals of politics become self-referential, professional and technocratic, and what little inter-party competition remains becomes focused on the efficient and effective management of the polity. The election campaigns that are conducted by cartel parties are capital-intensive, professionalized and centralized, and are organized on the basis of a strong reliance on the state for financial subventions and for other benefits and privileges. Within the party, the distinction between party members and non-members becomes blurred, in that through primaries, electronic polling, and so on, the parties invite all of their supporters, members or not, to participate in party activities and decision-making. Above all, with the emergence of cartel parties, politics becomes increasingly depoliticised.