Contemporary meritocratic education discourse in England positions schools as 'engines of social mobility', responsible for enabling students' educational 'success' regardless of their circumstances. Building on critiques that characterise meritocracy as a neoliberal cultural motif that legitimates inequalities, and the capabilities approach, this paper investigates the challenges of navigating meritocratic expectations in practice by drawing on qualitative and photovoice interviews conducted with teachers and students at a highly rated London school serving a disadvantaged community. While many participants endorsed meritocratic narratives, all expressed doubts that the school could 'make up for' the significant structural disadvantages faced by many students. This led our participants to describe challenges associated with meritocratic discourse, including: the stresses of meeting these expectations; uncertainty about attributing responsibility for 'failure'; and questions about what could and should be done in practice to enable disadvantaged students to 'succeed'. We argue that meritocratic rhetoric imposes significant burdens on students, teachers and schools by holding them responsible while obscuring the role that social inequalities play in shaping students' educational opportunities. Greater critical discussion in schools could help students and staff to challenge meritocratic education discourse and to negotiate its expectations.