Marks & Spencer launched its Plan A progamme in 2007 with the ambition to make the company the world’s most sustainable major retailer. This far-reaching ecological and ethical programme is now in its 9th year. In this interview, Mike Barry, who oversees Plan A, and was part of the initial team that developed the programme, talks about the progress that M&S has made hitting its targets, how M&S deals with innovation in sustainability, the challenges and lessons from integrating sustainability across the business-and why this is so crucial to the company’s future success.