He was educated at Brentwood School, read PPE at St John's College, Oxford and later took a Master's degree in War Studies from King's College London writing Tom Wintringham and the Socialist Way of War for the Institute of Historical Research in 1988, a paper which led to Wintringham's papers coming to King's, and formed the basis for much of Wintringham's biography as eventually written by Hugh Purcell. A keen cooperator, he served as Political Officer of the South East Co-op (Co-operative Wholesale Society) from 1987-1994. In 1994 he was elected LabourMEP for London South East. He served on the Agriculture and Rural Development committee. He was not re-elected in 1999 under the list system, and became Chief Executive of the Association of British Credit Unions Limited (ABCUL) which represents the vast majority of credit unions in Great Britain. Spiers has been Chief Executive of CPRE since 2004.