This paper draws on research in three English Midlands local education authorities to analyse the changing role of the teacher trade union representative in schools. It focuses on representatives of the largest teachers' union in England and Wales--the National Union of Teachers. The paper draws on mainstream industrial relations literature, and more recent research into school sector industrial relations, to assess how the role of the union representative is changing in an era of autonomous schools. The research indicates that new issues are emerging in schools, and these have the potential to transform the role of the representative. Where representatives can respond to the emergence of these new issues there is the prospect of a new, more participative trade union culture developing in schools. However, it is far from certain that school union representatives will want to assume these increased responsibilities, and this poses a major challenge for the development of teacher trade unionism.