Cape Town - Former Minister of Social Development Susan Shabangu has also resigned as ANC MP.
Parliament confirmed on Thursday that Shabangu has joined Nomaindia Mfeketo and Dipuo Letsatsi-Duba to resign as members of the national legislature.
Shabangu served in Cabinet in various portfolios in the past few years, first as deputy minister of police before she was appointed Minister of Mineral Resources.
Former president Jacob Zuma later moved her to the Presidency where she was minister of Women.
When President Cyril Ramaphosa took over in February last year he appointed her minister of Social Development.
This was at the time of the South African Social Security Agency debacle.
After the elections in May she was not appointed back into Cabinet.
Shabangu had also served as a member of the National Executive Committee of the ANC.
She is the fourth former minister to quit their MP posts and the second to announce their decision today after former state security minister Letsatsi-Duba. Jeff Radebe resigned a week ago and Mfeketo announced her resignation on Wednesday.