[1] He went to school in KwaMashu and then qualified as a chemical engineering technician at the Mangosuthu University of Technology; while a student, he was active in anti-apartheid youth politics.
[1] In 2002, Mthembu was elected Provincial Secretary of the KwaZulu-Natal branch of the South African Communist Party (SACP), the ANC's close ally.
[5] When Mchunu was finally removed as Premier in May 2016, he was replaced by Willies Mchunu, who, shortly after taking office, announced a cabinet reshuffle in which Mthembu was appointed to the KwaZulu-Natal Executive Council as Member of the Executive Council (MEC) for Agriculture and Rural Development.
[9][12] In the 2019 general election, Mthembu was re-elected to his seat in the provincial legislature, ranked 38th on the ANC's party list.
[14] Ahead of the SACP's next provincial elective conference in May 2022, Mthembu's re-election bid was not expected to face any significant opposition.