This article investigates the client-consultant relationship in the implementation of ERP using a case study of the human resources model in the government of Minas Gerais State, Brazil. The implantation of ERP and the client-consultant relationship have been thoroughly discussed for the private sector, but have yet to be well understood in a government context. To understand this dynamic, the theoretical framework of Pozzebon and Pinsonneault has been used, which suggests that knowledge and power are shared and negotiated during the implementation of configurable technologies such as ERP. The findings show a dynamic of cooperation between client and consultant due to mutual necessity, with diverse mechanisms of knowledge and power that influence the relationship. Between them, mechanisms that may be exclusive to the government scenario: the common language, the involvement of an external agent in the project and the external IT team. The study examines the application of the theoretical framework in a public sector context, providing insight concerning the client-consultant relationship in an arena where public expenditure on consultancy and management tends to increase. Owing to the particular nature of government, the study provides insight that can benefit governments and consultants in the implementation of successful ERP.