Zuma has been under growing pressure to resign since he was replaced as head of the African National Congress in December by his deputy Cyril Ramaphosa.
Signalling a clear shift in power, Ramaphosa on Saturday announced a new board for Eskom, the troubled state-owned power company that has been linked to graft allegations.
Zuma’s presidency has been engulfed by corruption scandals and a weakening economy, with the party losing public support ahead of next year’s general election.
Ramaphosa’s supporters are keen for him to take over as president immediately and try to revive the economy before the election, when the ANC could lose its dominance for the first time since the end of apartheid.
“The ANC must act decisively and with determination to rebuild the bond of trust between our people and the movement,” the party said after a two-day meeting of its senior members.
– Power rivals? –
The statement also addressed criticism that South Africa currently has two centres of power — Zuma still in office as president, while Ramaphosa heads the ruling ANC party.
“(Party) officials, led by President Ramaphosa, will continue their engagement with President Jacob Zuma to ensure effective coordination between the ANC and government,” it said.
The News 24 website said the party meeting on Thursday and Friday had decided that Zuma must leave office, but that no exact timeline had been agreed.
“We will have a new president in the coming weeks,” it quoted one unnamed party member at the meeting as predicting.
Eskom’s struggle to repay loans on its massive debts is seen as one of the biggest threats to South Africa’s economy.
Naming a new board was Ramaphosa’s first major public move to tackle the multiple fiscal challenges that face the country after nine years of Zuma’s rule.
“We are confident this intervention will restore the important contribution Eskom makes to our economy,” Ramaphosa said in a statement released on the presidential website.
“We are determined to address the damage that has been done to this institution.”
The statement added that the new board would sack at least two Eskom executives accused of serious corruption.
– Zuma’s power ebbs –
Many graft allegations against Zuma have centred on the wealthy Gupta family that is accused of unfairly obtaining lucrative government contracts and even being able to chose ministerial appointments.
Zuma’s closest allies still hold senior positions in the party, and he could in theory remain president until the 2019 election that marks the end of his second and final term in office.
His hold over the ANC was shaken when his chosen successor — his former wife Nkosazana Dlamini-Zuma — lost out to Ramaphosa in the closely-fought race to be party leader.
Zuma, 75, could leave office either by resigning, through losing a motion of no-confidence in parliament or impeachment proceedings.
He could also be recalled by the ANC, forcing him to step down.
Whoever is president on February 8 will deliver the annual state of the nation address to parliament — providing one deadline for political manoeuvering.
Ramaphosa, 65, is a former trade unionist who led talks to end white-minority rule in the early 1990s and then became a multi-millionaire businessman before returning to politics.
The ANC, which has ruled since 1994 when Nelson Mandela won the first multi-racial election, recorded its worst-ever results in 2016 local polls.