"Brian Molefe should never be a Member of Parliament. He is an ethically compromised 'Zupta' buddy with corruption clouds hanging over his head," said DA chief whip John Steenhuisen.
"This adds credence to the idea that Molefe has his eyes on the finance portfolio, and that a Cabinet reshuffle is imminent, just days before Pravin Gordhan is due to present the budget."
He said the nomination confirmed that the ANC did not care about fighting corruption.
"In fact, it seems you are more likely to rise in the ANC ranks if you are accused of corruption."
The former Eskom CEO who resigned under a cloud late last year, will soon be sworn in as a member of Parliament, the legislature confirmed on Friday.
“Parliament wishes to acknowledge the nomination of Mr Brian Molefe, to fill a vacancy on the North West list of ANC Members of Parliament, which is depleted,” spokesman Moloto Mothapo said.
“Presiding Officers of Parliament will determine a date for swearing him in as a Member of Parliament.”
Molefe quit in November, shortly after the release of former Public Protector Thuli Madonsela’s report “State of Capture” which detailed extensive contact between him and the politically-connected Gupta family.
She found indications that Eskom had bent over backwards to give a coal supply contract to Tegeta, one of the companies in their business empire.
Molefe is an enthusiastic proponent of contested plans to build new nuclear reactors to boost South Africa’s electricity generation capacity.
The DA laid criminal charges against Molefe after the release of Madonsela's report.
His nomination as an MP follow weeks of speculation that he would be given a seat on the African National Congress (ANC) benches to enable President Jacob Zuma to name him as a Cabinet minister, possibly in the place of Finance Minister Pravin Gordhan.
Gordhan is due to table the national budget next week, but his current term has been marred by political tension, included an aborted attempt last year to charge him fraud.