The reported decision to "recall" Mr Zuma followed marathon talks by senior party officials that continued into the early hours of Tuesday.
If Mr Zuma, 75, still does not budge, he will face a vote of confidence in parliament that he is expected to lose.
He has been leader since 2009 but has been dogged by corruption allegations.
The ANC has not officially confirmed its plans, but party sources have described them to South African media outlets and Reuters news agency.
