The National Union of Metalworkers of South Africa (Numsa) on Monday raised objections to the appointment of Eskom chairperson Jabu Mabuza as interim chief executive, saying it intends seeking legal advice on the matter.

Public enterprises minister Pravin Gordhan announced last week that Mabuza would serve as the interim CEO of Eskom for three months after Phakamani Hadebe's resignation left the position vacant.

In a statement, Numsa said that it would be irregular for Mabuza to be the chairperson of the board as well as the group chief executive.

The union said Mabuza was not fit to chair the Eskom board because he is allegedly conflicted as his family business has interests in Eskom, both in the boilers maintenance and supply of coal. 

Numsa said it seemed that Mabuza was appointed to the role, because he is one of the few executives trusted by the government to implement the mandate of restructuring Eskom to enable privatization.

Last week, Eskom reported that it had incurred a loss of R20.7-billion in the 2018/2019 financial year, up from R2.3-billion the year before as power sales generated insufficient income to cover its operating costs and interest payments.

"Numsa has consistently said that that the board and executive management team at Eskom are technically incompetent, and this has been proven to be correct," it said. 

"And this is why we repeat our demand that their dismal failure to lead and manage this strategic SOE means that Jabu Mabuza, together with the entire board and senior executive management of Eskom must be removed."