Transport, municipal and pharmaceutical workers across the country were set to down tools today after last minute wage talks deadlocked.
A strike in the rail sector, due to have started at 12am, could leave 1.5 million commuters stranded.
Chris de Vos, the general secretary of United Transport and Allied Trade Union (Utatu) said yesterday: "There have been no phone calls to give us indication they want to sign."
Utatu and fellow union the SA Transport and Allied Workers' Union (Satawu), wanted a seven percent wage increase from Metrorail, with an extra two percent in September. Together the two unions represent 10,000 workers.
Metrorail said it had contingency plans for the strikes, but warned customers to expect disruptions.
Municipal workers' union Samwu general secretary Mthandeki Nhlapho said "there is not any possible indication" that strike by the union could be averted.
At least 150,000 municipal workers were planning to stop work across the country.
Samwu and the Independent Municipal and Allied Trade Union both rejected an 11.5% wage increase offer.
The unions warned that essential services may be affected by the strike.
The city of Johannesburg was putting contingency plans in place and appealed to unions to ensure their members did not break the law during the strike.
Pretoria warned commuters the strike meant buses would not be running.
"Bus commuters should therefore make use of alternative modes of transport if the services are interrupted by the strike," councillor Gabriel Twala said.
"However, essential services, such as waste management and emergency services, should not be affected by the strike."
Metrobus in Johannesburg issued a similar warning.
The city of Cape Town warned that refuse collection in informal settlements, street sweeping, emptying of litter bins and removal of illegally-dumped material may be affected.
Thabani Mdlalose, deputy general secretary of the Chemical, Energy, Paper, Printing, Wood and Allied Workers' Union (Ceppwawu) told Sapa yesterday the strike would continue into the week.
Ceppwawu was planning protests Durban, Port Elizabeth and Cape Town.
The union had been briefing its pharmaceutical workers on a new offer by employers.
Mdlalose said pharmacists would also continue staying away from work until a settlement was announced.
Workers in this sector were offered a nine percent pay rise on Friday, which it would take to its members for endorsement.
Workers in the petroleum industry were due to join the strike this week.
The Communication Workers' Union would also continue demonstrations against Telkom and the SABC. The union was unhappy over wages, the threat of possible job losses and poor administration.