Johannesburg - The proposed increase in electricity prices will promote "izinyoka" or the illegal use of power, Gauteng Congress of SA Trade Unions secretary Dumisani Dakile said on Wednesday.
"Izinyoka" - the Zulu word for snakes - is a nickname given to people who connect electricity illegally.
Eskom has applied to National Electricity Regulator of SA (Nersa) for an electricity price increase of 16% every year for the next five years.
This would more than double the price of electricity over five years, taking it from 61 cents a kilowatt hour in 2012/13, to 128 cents a kWh in 2017/18.
Dakile was speaking at a Nersa public hearing in Midrand on the proposed tariff increase.
He criticised Nersa for not taking the hearing to the townships and warned of violent protests over the issue, similar to those seen recently in Sasolburg in the Free State.
"It is a grave injustice for you not to go there [to townships]," he said.
Sasolburg residents embarked on violent protests last week over a municipal merger proposal.
Dakile asked why Eskom was proposing these hikes for a five-year period and said previous hikes had been scheduled to run for three years.
"The 16% tariff hike is also three times more than the inflation rate... We are not prepared to accept it, " he said.
Dakile accused Eskom of not supporting the National Growth Plan and said it threatened to add to the crisis of unemployment.
"What Eskom wants to do to our people is a grave injustice... What is being introduced is another form of apartheid that says those who cannot afford electricity will not have it," he said.
Some in the auditorium greeted this remark with cheers and laughter.
Dakile called for the electricity provider to instead increase the amount of electricity it gave for free to the poor.
He said the poor were currently receiving 50kWh for free on a monthly basis. He proposed that it be taken it up to 200kWh.
President of the National Union of Metalworkers of SA (Numsa) Cedric Gina also addressed hearing.
He said the R1.9 trillion that Eskom needed to generate was exaggerated and included needless costs.
"The poor shouldn't be punished with outrageous hikes," he said.
Gina said these hikes threatened to make companies struggle and would see many of them shut down.
He urged the Nersa panel to investigate Eskom's senior managers, arguing that the company's managers had increased from 17 to around 33 in recent years.
He said Nersa should question this and also look into the salaries, bonuses and incentives that the managers were possibly reeling in.
The hearings continue on Thursday.
Earlier, around 100 people carrying placards blocked the gate to the premises.
Some of the placards read: "Eskom's application equals job losses and inflation" and "Link electricity tariff increases to inflation".
Two men wrapped in plastic, with electric cables around their necks, sprawled on the ground. Above their heads were cardboard tombstones with the words: "RIP Eskom, you are killing us".
Several elderly people were among the protesters. One shouted that Eskom was denying them their basic right to electricity.
Besides the proposed electricity hike, the group said they were against nuclear energy. According to one placard this was a "Nuclear Fukushima".
By the time the proceedings ended, all protesters had left the venue.