Mr Nkosi was a Member of the National Assembly from 1994 to 2001. Before returning to Parliament in 2019, he was a member of the Gauteng Provincial Legislature and a Senior Civil Servant at the Economic Development Department (EDD), which he joined in 2011. He was the first President of the South African Commercial Catering Workers Union (SACCAWU) and Chairperson of the South African Local Government Association (SALGA), Gauteng. He was also Executive Mayor of Ekurhuleni Metropolitan Municipality from 2001 to 2008.
