Frame Extension in a Mature Social Movement: British Trade Unions and Part-time Work, 1967-2002

Since the 1960s, British trade unions have developed a policy for representing the interests of part-time workers, a significant process of frame extension within a mature social movement. This article seeks to account for this change. It concludes that change was a product of the growth of feminist activism within unions, the deployment of instrumental and solidarity frames and a response to political opportunities provided by both the British state and European Union.