Former ministers Jeff Radebe and Siyabonga Cwele have also resigned as MPs after failing to crack the nod in President Cyril Ramaphosa's new Cabinet.
Parliament spokesperson Moloto Mothapo confirmed on Monday that Radebe and Cwele had tendered their resignations.
Radebe - a veteran of seven ministries going back to 1994 - said two weeks ago that he was ready to enjoy the routines of "normal life" and immerse himself into new possibilities.
The pair join a growing number of former ministers who have in recent weeks resigned as ordinary members of the National Assembly after being left out of Ramaphosa's recently announced Cabinet.
Last week, former minister of sport and recreation Tokozile Xasa joined former ministers Susan Shabangu, Dipuo Letsatsi-Duba and Nomaindia Mfeketo in submitting letters of resignation as MPs.
National Assembly Speaker Thandi Modise will on Monday swear in their replacements, although it is not immediately apparent who will be replacing Cwele.
ANC Chief Whip, Pemmy Majodina, previously confirmed that:
Fikile Masiko will replace Shabangu;
Former deputy minister of finance Sfiso Buthelezi will replace Letsatsi-Duba;
Tshoganetso Tongwane will replace Mfeketo;
Nombulelo Lillian Hermans will replace Silvia Lucas, who withdrew from the list due to her deployment as deputy chairperson of the National Council of Provinces;
Emily Manketsi Thlape will replace Ramaphosa, who ceased being a MP after his elections as president;
Judy Hermans will replace Xasa; and
Lindiwe Mjobo will replace Makhosini Nkosi, who did not take up his seat.