This article examines Engestrom's version of activity theory, one rooted in Marxism. It is argued that whilst this approach holds progressive possibilities, its radicalism is undermined by a restricted conceptualisation of transformation and the marginalisation of a politicised notion of social antagonism. As a consequence, this approach to activity theory can easily fold over into a conservative praxis that undermines its potential radicalism, becoming instead technicised and a form of transformism. (Contains 2 figures and 1 note.)