Addressing the media after an ANC Parliamentary Caucus meeting this afternoon, ANC Treasurer-General Paul Mashatile confirmed that 75-year-old Zuma had defied a recall from his party.
"The ball is in his court. We can't wait. It s not fair to South Africans, the ANC or anybody," Mr Mashatile said as he explained that if Zuma resigned by this evening, the motion of no confidence in Parliament would fall away.
"Should he resign, the cabinet stays and the Deputy President (Cyril Ramaphosa) takes over and we continue. However, if he doesn t resign and he is recalled, the whole cabinet goes. In that case the Speaker of Parliament will be the President until a new President is elected," Mr Mashatile said.
"There are no negotiations (with Zuma)," added ANC Chief Whip Jackson Mthembu who shared the platform with Mashatile.
A defiant Zuma refused to quit, saying he had been given no reason by the party why he should resign.
"It was very unfair to me that this issue is raised," he said in a TV interview. "Nobody has ever provided the reasons. Nobody is saying what I have done."
Mr Zuma has previously survived several motions of no confidence by opposition parties in the past.