Johannesburg - The National Union of Metalworkers of SA (Numsa) has accused Eskom of spending millions of rands on parties.
"This is a serious concern and a spit in the face of the workers and the poor, who are economically bleeding as a result of high electricity tariffs," the union said in a statement on Tuesday.
Numsa felt it was outrageous that those in positions of influence were squandering public funds.
The City Press newspaper reported on Sunday that the parastatal had spent over R36m on seven "family fun days" since October last year.
This included awarding a R4m contract to a company to plan and organise five "generational family days" for almost 12 000 people in Gauteng.
Fun days were also held in Witbank in Mpumalanga, Lephalale in Limpopo, Cape Town, and Durban.
Eskom spokesperson Hillary Joffe told the newspaper the fun days were to thank employees for their hard work and commitment to "keeping the lights on".
Numsa felt Eskom could have used the R36m to subsidise distressed companies to save jobs, instead of spending it on parties.
Eskom was not in the business of parties, but rather charged with the mandate of playing a key role in the development of the country, the union said.