Practical work has a long history in science education in the UK. This article explores how the influences of curriculum and assessment policy have shaped practical work over recent years. We argue that, together with changes in teacher training programmes, these influences have weakened science teachers' capacity to meet the challenge of calls for a greater emphasis on practical work in school science. We draw on evidence from a small-scale study of novice science teachers' confidence and skill levels in common practical tasks to argue that a significant gap exists that will render implementation of greater practical activity challenging.