The natural capital approach (NCA) has increasingly become mainstream in environmental governance. This approach involves highlighting the economic value of the natural environment in order to make better informed decisions. Despite its mainstreaming and growing appeal, critical voices endure. These critiques frame natural capital in the context of global neoliberalisation, primarily focusing on its adverse implications for the Global South. By contrast, this thesis examines the role NCA has in a national, developed, Western setting – where the issues created by global power imbalances and neo-colonialism are less pertinent. The UK is at the forefront of NCA, with its 25 Year Environment Plan outlining its ambition to embed the approach into environmental decision-making. This thesis adopts a poststructural approach in order to examine the underlying assumptions, constructions, and moral framework of the UK’s NCA. It constitutes a policy analysis that employs the tools of the ‘What’s the Problem Represented to be?’ approach to three distinct sites of analysis - nature, instrumentation, and justice. Findings point to how NCA rests on a number of contingent assumptions, produces specific problematisations, subjects and objects, and ultimately derives from a presentism ethic.