How much freedom of action does an ambitious reforming party have as it moves from opposition to government? Drawing on original research and first-hand interviews, Andrew Connell analyses the development of welfare reform policy following New Labour's ascent to power in 1997 to show how ideas, actors, and structures can constrain policy options. He looks at the contrasting ideas of Frank Field, Minister for Welfare Reform in 1997-8, and of Gordon Brown, and shows how Brown's approach eventually came to prevail. The book also includes a unique exposition of Field's political and social philosophy, showing how his consistent Christian socialist beliefs influenced his work as Minister for Welfare Reform. Welfare Policy under New Labour will be essential reading for scholars of contemporary politics and social policy and for those interested in New Labour and welfare reform.