JOHANNESBURG — Splits in South Africa’s ruling party are widening because of unease over the leadership of President Jacob Zuma, whose apology for his handling of a spending scandal has failed to quell calls for his resignation.

Zuma retains the support of powerful factions in the ruling African National Congress party, and on Wednesday he set Aug. 3 as the date for local elections that will test whether the opposition can capitalize on discontent with the president and gain at the polls.

Additionally, the South African Parliament on Tuesday defeated an opposition motion to remove Zuma after the country’s top court ruled that he violated the constitution in a scandal over millions of dollars in state spending on his private home.

Yet some prominent figures whose association with the ANC dates to its role as an anti-apartheid movement decades ago have said Zuma should quit.

On Wednesday, ANC veteran Cheryl Carolus joined activists, including church officials and academics, at a news conference outside the Constitutional Court where speakers denounced alleged corruption under Zuma’s administration.

‘‘This has happened on our watch,’’ said Carolus, who described herself as ‘‘deeply saddened.’’

Trevor Manuel, a former finance minister, and Ahmed Kathrada, a former anti-apartheid activist who was close to Nelson Mandela, have also urged Zuma to resign.

Those backing the campaign include the Anglican Church of SA, the Evangelical Alliance, the South African Christian Leadership Initiative, and the United Front.

The ANC’s parliamentary bloc said in a statement that Zuma was committed to paying back some state money spent on his Nkandla residence in line with a Constitutional Court ruling.

Associated Press