Background In total, 81% of women in the UK start breastfeeding, but fewer than half continue beyond 6 weeks. Peer support in the early postnatal period may encourage women to breastfeed for longer. Objective To develop a breastfeeding peer-support intervention based on motivational interviewing (MI) for breastfeeding maintenance and to test the feasibility of delivering it to mothers in areas with high levels of social deprivation. Design Intervention development and a non-randomised multisite feasibility study. Setting Community maternity services in three areas with high levels of social deprivation and low breastfeeding initiation rates in England and Wales. Participants Pregnant women considering breastfeeding. Women who did not plan t...