He was Senior Policy Adviser to Jack Straw when he was the Home Secretary from 1997 to 2001. He chaired the National Inquiry into Selection, Development and Management of Staff in Children's Homes in 1992.
He was created Baron Warner, of Brockley in the London Borough of Lewisham on 29 July1998 and was a Minister of State at the Department of Health from the summer of 2003 until December 2006. He was appointed to the Privy Council in June 20061, and was sworn in on 19 July2006. In March 2008 he joined Deloitte as strategic adviser.