As delegates cast the last few ballots, senior members built up battle lines on social media, backing either Deputy President Cyril Ramaphosa or Nkosazana Dlamini-Zuma – a former cabinet minister and the ex-wife of President Jacob Zuma.
The vote is perhaps the most pivotal moment for deeply divided African National Congress since it launched black-majority rule under Nelson Mandela’s leadership 23 years ago.
Whoever emerges at the helm of the ANC, a 105-year-old liberation movement that dominates Africa’s most industrialised economy, is likely to become the country’s next president after elections in 2019.
“It is going to be very close,” a senior ANC source said. “Both camps have spreadsheets where they have calculated the number of delegates on their side. Both sides have different assumptions and guesswork.”
A total of 4,776 delegates began casting their ballots in the early hours after the vote, planned for Sunday, was delayed.
Ramaphosa, a former trade union leader who became a businessman and is now one of the richest people in South Africa, has vowed to fight corruption and revitalise the economy, a message hailed by foreign investors.
Dlamini-Zuma – the current president’s preferred candidate – has pledged to tackle the racial inequality that has persisted since the end of white-minority rule.
They were the only candidates nominated for the ANC leadership at a conference in Johannesburg on Sunday night.
“Delegates are very exhausted,” an ANC source who is a voting delegate told Reuters. “I don’t know how they will run today’s sessions.”
The party’s Chief Whip Jackson Mthembu announced on Twitter that he voted for Ramaphosa, while police minister Fikile Mbalula tweeted that he had cast his vote for Dlamini-Zuma.
In a boost to Ramaphosa, courts ruled that officials from some provinces seen as supporting Dlamini-Zuma had been elected illegally and were barred from the conference.
The rand currency gained after that news on Friday, extending its gains to more than 2 percent on Sunday, but was volatile early on Monday morning..
“Volatility will be high in the morning and explosive once the results are released. Most of the market reaction will be about who wins the presidency,” Rand Merchant Bank analyst John Cairns said.
ANC spokeswoman Khusela Sangoni said voting was expected to be completed by midday and results announced later on Monday.
“That announcement that we are all waiting for will happen am sure in the early part of the afternoon,” she said.
On Saturday, Zuma announced plans to raise subsidies for tertiary colleges and universities, a move analysts said was timed to appeal to the party’s more populist members allied to Dlamini-Zuma, the first woman nominated as an ANC presidential candidate.
Zuma has faced allegations of corruption since he became head of state in 2009 but has denied any wrongdoing.
Ramaphosa drew the majority of nominations from party branches scattered across the country. But the complexity of the leadership race makes it uncertain he will win the final count.
“The race is extremely close,” said Susan Booysen, a political analyst at the University of Witwatersrand’s School of Governance in Johannesburg.
“Before today we said Dlamini-Zuma could emerge as a winner. Even if there is a strong lead in terms of branch nominations by the Ramaphosa camp, it’s not clear-cut.”