The man set to become co-leader of Britain's second biggest union is largely unknown outside of local union politics.

Derek Simpson is an old-fashioned left-winger; he was a district officer for the Amicus union in Sheffield before the ballot which went to a fourth count.

He made a legal challenge to Sir Ken Jackson, arguing there should be a leadership ballot for the post of general secretary.

Simpson, 57, is a former member of the Communist Party but there are few senior figures in the union movement who did not flirt with the hard-left during the 1970s and 1980s.

He comes from a traditional union background - having started as an apprentice in a Sheffield engineering firm

His career as a union official began as Sheffield district secretary in 1981 for what was AEEU.

Simpson has been a member of the Labour Party for a decade but, unlike Sir Ken, he is not a Blairite.