Opposition to Zuma within the ANC's ranks has mounted since he fired Pravin Gordhan as finance minister and made 19 other changes to the executive on March 31 - a move that sparked public protests and cost the country its investment-grade credit rating.
The NEC does not usually vote on issues and relies on convincing members to reach a final decision. ANC lawmakers occupy 62 percent of the 400 seats in the National Assembly. It suffered its worst-ever electoral performance in an August municipal vote when it lost control of Johannesburg, the economic hub, and Pretoria, the capital.
A string of ANC allies have also urged Zuma to go, among them the Congress of South African Trade Unions (Cosatu), the South African Communist Party (SACP) and the South African Council of Churches (SACC).
"This will be a critical meeting for the NEC", said Ongama Mtimka, a political science lecturer at the Nelson Mandela Metropolitan University in the southern city of Port Elizabeth, who says there is probably an even chance of him being removed.
A man casts his ballot during South Africa's local government elections in KwaMashu, north of Durban, South Africa, August 3, 2016.
Zuma faced down calls to resign over those claims, which both he and the Guptas have denied.
President Zuma, however, survived a recall.
He said on Friday he was "not opposed to establishing a commission of inquiry", without specifying a timeframe. ANC spokesman Zizi Kodwa didn't answer calls seeking comment. He would step down at the party's elective conference in December, he reportedly said.
Mr. Zuma has been South African president since 2009 and won re-election in 2014.
At 0645 GMT, the rand traded at R13.0500 per dollar, 0.6% weaker from its NY close on Monday. By 06:05, the rand had returned to R12.86 to the greenback.
"If the opposition truly held the interests of the country at heart, as they publically state, they would withdraw the motion of no confidence and allow members of the ANC caucus to uphold the constitution of the country and show the necessary leadership that the country expects by formally moving a motion of no confidence themselves".
It's the second time in six months that Zuma has survived an open revolt from within his organisation.
The rand tracked weaker against the greenback after Zuma crushed dissent at a key ANC meet.
The 70-year old leader was backed by more than 50 of the 70 members of the National Executive Committee that debated removing him, South Africa's News24 reported.
The NEC's failure in leadership placed ANC members of Parliament in the "invidious position" of having to reach a decision as to whether their own Parliamentary oath has any real meaning.
"I have been quiet because I don't want to harm the ANC, so continue attacking me in the media and you will see", Zuma is quoted as saying to the ANC NEC.