26

This paper is concerned with trade unionism as a work activity. An intervention in occupational psychology (more specifically in a clinical approach to activity) involving a group of trade unionists was led within a departmental section of a teachers’ union from the perspective of developing their power to act. After more than two years of group work, the intervention stopped suddenly, at the moment when the debates on possible transformations were beginning. It is in wanting to understand this interruption and the obstacles met throughout the intervention that a particularity of the organization of work appeared: its fuzziness. Yet this fuzziness would be the consequence of certain principles that founded the trade union, thus making it difficult to envisage possible transformations