Critical Discourse Analysis (CDA) explores the role of discourse structures in constituting social inequality. Metaphorical structure, however, has received relatively little attention in explicit CDA. The paper aims to redress this by developing a coherent theoretical framework for CDA and metaphor. This framework adopts conceptual blending theory over conceptual metaphor theory, where the latter is perceived to be incompatible with CDA. The framework is applied in a CDA of metaphors for nation and immigration in the British National Party's 2005 general election manifesto.