Policy-makers are currently seeking to transform prison regimes so that they prepare prisoners for the labour market. However, this article shows that the alleged poor work ethic of prisoners has traditionally been viewed as a key element in their classification as the ‘undeserving poor’ and that economic transformation has relegated many to the margins of the labour force. This raises important questions about the role of prison in the post-industrial labour market. The author argues that prison simultaneously houses the growing surplus population resulting from capital’s unceasing drive for profit and becomes a lucrative new market which has transformed some prisoners into an economic resource.