A Moody's analyst expressed concern about the possible impact of some ANC documents to be discussed at the party's policy conference next month, according to Thursday's Business Report.
Kristin Lindow, Moody's lead South Africa analyst, said they noted a "definite change" in economic policy with an "interventionist" approach to the mining sector and threats to property ownership.
Speaking on the sidelines of the Moody's investors service sub-Saharan Africa credit risk conference in Johannesburg, she warned that further signs that populist pressures were driving government policy in the wrong direction could trigger a rating downgrade.
"The conference in June will give us some clarity about where (the) government is going," she said.
Ratings determine the interest governments pay on their borrowings - the lower the rating, the higher the bill.
Moody's currently has South Africa on a rating of A3 -- four notches above the lowest investment grade.
In some ways South Africa was moving towards Baa country medians --referring to indicators like enforcement of contracts, predictability of policy making and press freedom.
Last November, Moody's changed the country's sovereign outlook from stable to negative.
A negative is when the government underwrites the rising debt of public enterprises and other state institutions.
An example of this is the government having to help the SA National Roads Agency Ltd service its debt on e-tolling since the system was put on hold.