The nearly two million-strong Congress of South African Trade Unions (Cosatu) said the action will be a warning to employers who may want to sack workers because of a downturn in profits due to a power supply crisis.

"We are adamant that workers should not be asked to pay for government's failure to invest in electricity," Patrick Craven, Cosatu's spokesman said.

Workers fearful

South Africa's mine workers are particularly concerned about possible job cuts because a five-day power cut in January and the rationing of electricity to mines has cut output and earnings.

Anglogold Ashanti said the one-day strike would shut down all of its mines in the country.

"There will be a widespread impact," Alan Fine, a company spokesman, said. "All of our operations will be shut down."

Anglo Platinum, the world's top platinum producer, and Impala Platinum, ranked second, may also be disrupted.

BHP Billiton's aluminium smelters, Anglo American's coal and iron ore mines and refineries on South Africa's coastline could also be affected.

A national strike would grow to affect refineries, car makers, textile factories, businesses and the construction of stadiums meant for the 2010 Soccer World Cup.