The National Union of Metalworkers of South Africa (Numsa) says the "disastrous" Independent Power Producers (IPP) programme to be implemented by power utility Eskom could cost the country thousands of jobs.
The workers union marched on Union Buildings on Saturday to hand over a memorandum protesting the signing of IPP contracts and the possible privatisation of Eskom.
Numsa head Irvin Jim said Eskom was "systematically and deliberately" destroyed.
He said that the Eskom board, senior management and the state have been promoting "the disastrous IPP programme".
"The ANC government has betrayed the working class again by finalising these contracts. The IPP's will destroy Eskom... it will lead to the destruction of almost 100 000 jobs in the country, the majority of which are in Mpumalanga."
Jim also rejected the plan to close power stations that reach the end of their life cycle.
"For all these years, Eskom boards that acted in the interest of Eskom have always extended the life span of the power stations. This is what this current board is failing to do; it is failing to do so because it is a board for IPPs."
Not against an energy mix
Jim said that while Numsa was not against renewable energy there "must be a just transition, that we must have a socially owned renewable sector".
"This is why we reject the reckless decision by Minister Jeff Radebe of the unilateral signing of the 27 IPPs without following the law where Nersa should have called for public hearings."
He said that IPP's should be disconnected from the national grid and for the life cycle of Eskom power stations to be extended to 2030.
"The operation life of Eskom power stations should be the 60-year life, which the board approved in 2016; and we must all commit that all the old Eskom power stations be decommissioned by 2030."
He also called for a national dialogue on what kind of energy mix SA needs.