From Longman Dictionary of Contemporary Englishhatchet manˈhatchet ˌman noun [countable] informal BBBsomeone who is employed to make unpopular changes in an organization
Examples from the Corpus
hatchet man• Far worse than an ineffectual president would be an ideologically motivated hatchet man.• Crucial to Mbeki's back-room operation are his deputy minister, Essop Pahad, considered the parliamentary hatchet man.• And he went head on against the notion that he would be an unfeeling hatchet man against the government.From Longman Business Dictionaryhatchet manhat‧chet man /ˈhætʃət ˌmæn/ noun (plural hatchet men) [countable] informalHUMAN RESOURCES someone employed to make unpopular changes in an organization, especially ones which involve people losing their jobs 