“The ANC has learnt with sadness about the passing away of Mrs Masefako Sophia Motlanthe, the mother of Deputy President Kgalema Motlanthe,” spokesman Jackson Mthembu said in a statement.
“The passing of Mrs Motlanthe, while not unexpected as she was of advanced age, is a loss not only to the Motlanthe family. It is a loss to the ANC family and indeed the entire South African society.”
She died of natural causes at her home in Meadowlands, Soweto, on Friday, aged 89.
A memorial service would be held on Thursday, and the funeral on Saturday.
She died a day before Motlanthe’s wedding to long-term partner Gugu Mtshali in Houghton, Johannesburg.
The ANC wished the Motlanthe family strength.
“To the Motlanthe family we say: take solace from the knowledge that all South Africans share your pain and are with you as you prepare to lay to rest your beloved mother,” said Mthembu.