South Africa's trade union federation has threatened with strikes before October over substantial electricity price rises.
Anger is widespread in South Africa over the power price increases, which will mean a rise of more than 25% this year and even more in subsequent years.
The increases fell short of Eskom's request for a 35% hike annually over the next three years, reports Reuters.
The union has declined to say whether action could start before the soccer World Cup in June.
"The last thing we want to do is disrupt the World Cup but our interest is bigger than the World Cup," COSATU secretary general Zwelinzima Vavi told Reuters reporters.
State utility Eskom plans to raise ZAR461bn (US$62bn) to build more plants and avoid blackouts such as those that affected the mining industry in 2008.