The British National Minimum Wage was introduced in 1999 under the guidance of a Low Pay Commission constructed on a basis of ‘social partnership’. The article analyses its conduct over its first 10 years from diary data. Key challenges were for it to be independent of government, to have its advice accepted by government and to maintain internal unanimity. The changing internal dynamics of the Commission, and its major negotiations over the level of the minimum wage, are described and analysed. Conclusions are drawn for the social partnership process.