One of the most divisive figures in South Africa, Zuma was president from 2009 until 2018, when he was forced to quit following a string of corruption scandals involving his administration.

Openly hostile to his successor President Cyril Ramaphosa, Zuma announced in December he would not vote for the ruling African National Congress, his longtime party, in the May 29 election, instead backing new party uMkhonto we Sizwe (MK).

With polls suggesting the ANC will lose its majority for the first time since it came to power in 1994, smaller parties like MK could potentially gain leverage after the election in a scenario where the ANC is looking for coalition partners.

Support for MK has hovered between 8% and 13% since Zuma's endorsement, according to polls. Zuma has become the party's public face despite remaining an ANC member.

But after Zuma fell out with MK founder Jabulani Khumalo and ousted him from the party, Khumalo has hit back by writing to the electoral commission saying Zuma was not the rightful leader of MK and his face should not appear on ballot papers, SABC reported.

A spokesperson for MK said Zuma was the party's president and Khumalo had been expelled. The electoral commission said it did not wish to involve itself in internal party disputes and Zuma had been the registered leader of MK since April 10.

In a measure of Zuma's perceived potential for causing disruption, the ANC postponed a disciplinary hearing against him that was supposed to take place this week, citing security concerns ahead of the election.

Zuma remains a force in South African politics, especially in his home province of KwaZulu Natal where protests erupted in 2021 after he was jailed for refusing to participate in a corruption inquiry.

MK is named after the ANC's former armed wing in the apartheid era.