This paper explores the impact of subject-specific mentoring within post-compulsory education. Using questionnaires and semi-structured interviews, it considers those factors considered "most useful" to teachers in training. The findings suggest that, contrary to the views espoused by bodies such as the Office for Standards in Education, Children's Services and Skills, mentors have a limited impact on the effectiveness of teacher education. Reasons for this are examined, including the context in which most trainees and mentors work as well as the restrictions created by initial teacher education frameworks. A more productive approach to supporting post-compulsory education trainees is explored through the development of a collaborative and democratic model of mentoring.