Johannesburg - The 16% increase in electricity tariffs will have a negative affect on the economy, ANC secretary general Gwede Mantashe said on Monday.
"Something will have to be done not to allow it to go to those levels," Mantashe told reporters in Johannesburg.
The increase would affect industrialisation, employment retention, and the productive capacity of the economy.
"We must not just look into the tariff, we must also take into account... the importance of ensuring that there is security of supply. So we don't only look at one side," he said.
A balance between the two was necessary.
Mantashe said the increased electricity tariff was discussed at the African National Congress's lekgotla last week in Irene, Pretoria.
Eskom applied to the National Energy Regulator of SA (Nersa) in October for a 16% increase in electricity prices each year for the next five years.
This would take the price of electricity from 61 cents a kilowatt hour in 2012/13 to 128 cents a kWh in 2017/18, more than doubling it.
Nersa held public hearings on the increase last week and is expected to announce its decision in February.