South Africa's President Cyril Ramaphosa is in a tight party leadership race against his former health minister - who he forced to resign amid corruption allegations.
Zweli Mkhize is enjoying a last-minute surge at the African National Congress conference in Johannesburg, reports say.
The candidates are fighting for the support of some 4,426 delegates.
The winner will lead the party to the next general elections in 2024.
If Mr Mkhize does win he would become ANC leader, but Mr Ramaphosa would remain president.
Mr Ramaphosa had faced calls to resign ahead of the conference over an alleged cover up of theft of a large sum of foreign currency that was hidden in a sofa at his private farm.
An independent report commissioned by the speaker of parliament said Mr Ramaphosa may have broken the law but he has denied any wrongdoing.
On Tuesday, ANC MPs were instructed to back Mr Ramaphosa and vote down an attempt to start an impeachment process. Only a handful defied the whip clearing a huge hurdle that would have locked him out of the party leadership race.
On Friday, some delegates heckled Mr Ramaphosa, with some displaying the name of his Phala Phala farm where the theft took place.
Mr Mkhize's supporters also chanted "change" and "He [Ramaphosa] is not coming back!"
The former health minister was forced to leave office last year after allegations emerged that a communications company linked to his family benefited from a contract at the height of the Covid pandemic. He has denied any wrongdoing.