Despite increases in educational attainment in London, too many mathematics lessons remain focused on factual recall and procedural understanding,resulting in disaffection among learners. This study reports on the establishment of a research group, comprising five teacher researchers and myself, which aimed to challenge this situation through adopting a participatory action research methodology. By planning, teaching, and evaluating innovative classroom activities, the group demonstrated how making mathematics more relevant and meaningful can enhance students' engagement and agency. The collaborative and mutually supportive nature of the group developed teacher researchers' self-efficacy in addressing issues of social justice in their mathematics classrooms.