"Should government persist in its naive and dangerous management of Telkom we may soon see the company come cap-in-hand to Parliament asking for a financial lifeline," Democratic Alliance MP Marian Shinn said in a statement.
"Government has a dismal record in managing state-owned companies and Telkom must not be allowed to become another state-controlled failure," she added.
The DA's comments follow Monday's announcement that Telkom chief executive Nombulelo "Pinky" Moholi had resigned.
"The news is further proof that seasoned professionals find Communications Minister Dina Pule's amateurish and her reckless meddling in the affairs of a listed company intolerable," Shinn said.
"This [meddling] has jeopardised the operations of the listed company."
The company's board director Neo Phakama Dongwana also resigned.
Once the "current vacancies" on the board were filled, it would start looking for a new chief executive.
