This paper examines the way in which different speakers may construe both the context and the categories involved in a single event. This is achieved through an analysis of Margaret Thatcher's and Neil Kinnock's leadership speeches to their respective party conferences during the British miners' strike of 1984–5. The analysis shows that both speakers construe the nature of the event such that their party is representative of an ingroup which encompasses almost the entire population and such that their policies are consonant with the definition of the ingroup identity. Thus their category constructions mirror the ways in which the respective leaders seek to mobilize the electorate during the strike. This analysis is used for two purposes: firstly, to argue for an integration of self-categorization theory with rhetorical/discursive psychologies and hence for further research into the ways in which self-categories may be contested in argument rather than determined by cognitive computations; secondly, to argue for further research into how political rhetoric may affect mass action through the ways in which collectivities are defined.