A major South African trade union said on Sunday it would go ahead with its plan to embark on a massive strike in the metals and engineering sector next week.
The National Union of Metalworkers of South Africa (NUMSA) made the announcement after wage talks failed.
"The national executive committee has agreed to the decision from our members to embark on an indefinite strike action, beginning on Tuesday," said Irvin Jim, NUMSA general secretary.
There have been calls for the union to refrain from the industrial action which would further hit the South African economy still reeling under a five-month platinum strike that came to an end last Wednesday.
"This was not an easy decision but a painful one, since the principle of 'no work, no pay' will be applied by the intransigent bosses," Jim told a press conference in Johannesburg.
He said that since the workers' demands were not met, the union has "no option but to allow our members to liberate themselves."
The union demands a 12-percent wage increase, nearly twice the current inflation rate, but employers agrees to only a 5.6-percent rise.
About 220,000 workers of NUMSA's 300,000 members are expected to take part in the nationwide strike.
According to Jim, thousands of NUMSA members would also picket at the headquarters of Eskom, the state-run electricity utility on Wednesday, July 2, raising fears for power disruptions at a time when power supply is severely strained. Eskom is the largest power supplier, providing nearly all electricity in the country.
The South African government has vowed to do everything in its power to prevent the strike from going ahead.
Minister of Telecommunications and Postal Services Faith Muthambi on Friday voiced concern over the potential harm that the strike would do to the economy.
The employers and union must be able to resolve their negotiations speedily in order to avoid such a strike, Muthambi said.
The strike by the metalworkers will effectively erase the opportunity for South Africa to redeem itself, and government bonds will most certainly be downgraded, according to the South African Chamber of Commerce and Industry (SACCI).
The platinum strike already prompted two international rating agencies -- Fitch and Standard and Poor's -- to downgrade South Africa's rating earlier this month.
South Africa has less than six months left to convince credit rating agencies and the international community in general of its stability as an investment destination, which will require above- average levels of production and economic activity, SACCI said.
This will in turn lead to higher cost of credit for the entire economy, from large corporate bonds to consumer credit, said the chamber.