The federation called for the government to set up a national food price regulator to determine prices and for heads of companies found guilty of price collusion to be dismissed. However, it had not yet decided on the form of the action to be taken.

"Although the precise dates and nature of the protest action will be determined ... the action will include marches, demonstrations and stayaways," said COSATU, which sits in a formal alliance with the ruling African National Congress.

Food prices has been rising sharply in South Africa, as in other parts of the world, and helping to drive up inflation to a 5-year high, prompting a series of interest rate increases.

Food inflation accelerated to 14.1 percent in February, outpacing targeted CPIX inflation of 9.4 percent year-on-year.

COSATU said in statement the government should protect the poor from sharp increases in prices, which had been exacerbated by higher interest rates and rising fuel costs.

"For more than a year now, food prices have been rising much more rapidly than overall inflation," it said.

"Food manufacturers and retailers have now increased the prices of basic foodstuffs, in some cases in collusion with one another, beyond the reach of the majority of the workers and poor people of our country."

South Africa's central bank has raised its repo lending rate by 400 basis points to 11 percent since June 2006 to try tame inflation, driven largely by food and fuel.

It left the rate steady in January but some analysts predict another increase on Thursday after inflation quickened some that expected.