Chapter 13 focuses more specifically on supermarket power and explore how efficiency and fairness become interdependent discourses in supermarket-supplier relations. Concentration in large grocery retail, in conjunction with associated growth in private labels and retailer control over shelf space, have generated a substantial power imbalance between big supermarket chains and the businesses that supply them. Supermarkets are said to be exploiting the imbalance to their own advantage, spawning a growing chorus of complaints from suppliers and from their representative organisations and political supporters. It has also garnered intense media, political and regulatory attention across a range of jurisdictions. This Chapter uses the analytical technique of problematisation to demonstrate how the “problem” concerning supermarket-supplier relations involves two distinct discourses relating to competition, on the one hand, and fairness, on the other. It highlights both potential tensions and interdependencies between these discourses and explores how they have been salient in both framing the aforementioned problem in public and policy debates and shaping regulatory responses. In particular, it critically examines the emergence of codes of conduct as a response to this problem drawing primarily on experience in Australia and to some extent, by way of comparison, the United Kingdom.