 Brumwell was born in Hartlepool, and was apprenticed as a joiner to the local shipbuilding firm of William Gray before moving into the construction industry.He joined the Amalgamated Society of Woodworkers, and became a full-time district official in Sheffield in 1971, the year that it joined the amalgamated organisation of UCATT.In 1974 he became the regional secretary in Leeds, and from 1984 represented the Midlands and Yorkshire on the union's executive council.