JOHANNESBURG - South Africa's highest court weighed on Monday whether lawmakers can cast secret ballots in a no-confidence vote in President Jacob Zuma, who faces growing criticism within the ruling ANC.
The Constitutional Court heard legal arguments in favour of the secret ballot.
Opposition parties have lobbied for a secret ballot and called for African National Congress (ANC) lawmakers to "vote with their conscience".
"ANC members of parliament will have to choose between what is best for themselves and what is best for South Africa," Mmusi Maimane, leader of the main opposition Democratic Alliance party, told protesters outside the Constitutional Court.
"They did not swear (their oath of office) to be faithful to Jacob Zuma, or to the ANC... They promised to be faithful to South Africa."
The case united DA protesters with marchers from the radical leftist Economic Freedom Fighters (EFF) party, with the court reserving judgment.
The scheduled no-confidence debate has been postponed by parliamentary Speaker Baleka Mbete, who has said she has no powers to agree to a secret ballot.
Zuma's sacking of respected Finance Minister Pravin Gordhan in March fuelled public anger over years of government corruption scandals, record unemployment and slowing economic growth.
- Legal battles -
The president has recently faced unprecedented criticism from senior ANC figures, including from Deputy President Cyril Ramaphosa.
Zuma, who came to office in 2009, is due to step down as head of the ANC in December, and as national president ahead of the 2019 general election.
He is seen as favouring his ex-wife, former African Union chief Nkosazana Dlamini-Zuma, to succeed him -- rather than Ramaphosa.
Zuma has been accused of being in the sway of the wealthy Gupta business family, allegedly granting them influence over government appointments, contracts and state-owned businesses.
The dismissal of Gordhan saw the Fitch ratings agency as well as Standard and Poor's cut South Africa's sovereign credit rating to junk status due to fears of political instability and growing corruption.