South Africa’s ruling African National Congress should discipline President Jacob Zuma for bringing the party into disrepute, housing minister and presidential hopeful Lindiwe Sisulu said on Friday.

Sisulu’s comments are the latest swipe taken at Zuma by former allies as the ANC fractures ahead of an elective conference in December where a new party leader will be chosen.

Zuma can remain head of state until a 2019 parliamentary election.

Sisulu, a veteran cabinet minister who comes from a prominent family in the struggle against apartheid, is seen as an outside bet to succeed Zuma.

She said a report presented at the ANC’s policy conference in July found that scandals surrounding Zuma had caused tensions and disquiet within the party.

“If we all agreed at the policy conference that that is what happened to the president, why was he not taken through a disciplinary process?” Sisulu told Eyewitness News, a domestic news service.

“I have been insisting that there must be a disciplinary process so that if there is an interpretation that you put the ANC into disrepute, that is an offence.”

Spokesmen for Sisulu and Zuma did not respond to calls for comment.

Members of the ANC have called for Zuma to step down in recent months following a series of corruption scandals, a much-criticised cabinet reshuffle and a failure to handle an economy that slipped into recession this year.

Lawmaker Makhosi Khoza, a strident critic of Zuma, quit the ANC on Thursday, labelling Nelson Mandela’s 105-year-old liberation movement “alien and corrupt”.

Nkosozana Dlamini-Zuma, former chair of the African Union and Zuma’s ex-wife, and Deputy President Cyril Ramaphosa are viewed as the frontrunners to take over as ANC leader.

Dlamini-Zuma has the support of Zuma’s powerful faction within the ANC while unionist-turned-business tycoon Ramaphosa is more popular with investors.