A changing socio-economic environment and competition have led trade unions to extend their role and become service providers. This paper examines some of the issues of service delivery which arise. Four central implications are discussed: the trade union's need (1) to adapt to the competitive service provider's market, (2) to enlarge its consumer body, (3) to become an employer of workers, and (4) to expand its interests with business establishments and authorities over non-union matters. The paper focuses on the General Federation of Labour in Israel (the Histadrut), and its comprehensive health insurance scheme (Kupat Holim). The scheme is provided to all union members and their families as part of union membership. Nonetheless, alternative service systems seem sufficiently attractive for many union members to consider ‘deserting’ their union. The union depends on its members—consumers—to secure its broad base, universalistic image, source of income and legitimacy. Trying to attract consumers causes the union to bend some of its principles. Ultimately, service provision forces the union to adopt characteristics alien to, and even contradicting, its traditional, militant role as an organiser of labour.