South Africans were gearing up for a no-confidence motion against President Jacob Zuma, who stands accused of abusing his power after a string of corruption scandals.
Parliamentarians will vote from 2 pm (1200 GMT) on Tuesday through secret ballots, raising the chances of the 75-year-old president being removed from office.
Protesters started to fill the streets of Cape Town, where South Africa’s parliament is located, from the morning, with banners urging legislators to “Fire Zuma.”
Large buses filled with opposition supporters rolled into town, causing heavy traffic.
Mmusi Maimane, the leader of the main opposition Democratic Alliance (DA), was scheduled to address the crowds at 12:30 pm (1030 GMT) in front of parliament.
Police officers were patrolling the streets, while roads leading towards parliament were blocked off.
Zuma has survived seven no-confidence votes since he became president in 2009. But they were held via open ballots, forcing members of the ruling African National Congress (ANC) to toe the party line.
Nine of a total of 13 parties requested a secret ballot, which will for the first time allow members of Zuma’s deeply divided ANC to vote against him without fear of reprisals.
For parliament to oust Zuma, at least 50 of the ANC’s 249 legislators would have to vote against the president, in addition to all the opposition lawmakers in the 400-seat assembly.
The president and his cabinet would then be forced to resign, following which parliament would elect a new president from among its members, or early elections would be held.
The no-confidence vote was proposed by the DA in April after Zuma fired respected finance minister Pravin Gordhan, prompting two ratings agencies to downgrade South Africa’s credit rating to junk.
The downgrades followed a series of corruption scandals, and Zuma is also under fire over his handling of the economy. Nearly 28 per cent of the workforce is unemployed, according to figures published Monday.
Zuma’s critics see him as having delegitimized the ANC, the liberation movement that has governed South Africa since the election of Nelson Mandela as the country’s first democratic president put a definitive end to apartheid in 1994.