Eight Cosatu-affiliated unions have declared a wage dispute with the government - the first step to a full-blown strike.
Eight unions affiliated to the powerful Congress of South African Trade Unions (Cosatu) said on Wednesday they had taken the decision after the government withdrew an enhanced offer of a 6.9% wage increase and reverted to an earlier 6.7%.
The unions, whose members include teachers and health workers, are asking for a 7.9% hike.
Declaration of a dispute is the first step towards launching a strike.
In its February budget, the government allowed for a wage increase of only 5% for public servants, adding that a huge state salary bill was crowding out investment in infrastructure and other key productive sectors.
The government has faced hundreds of protests in poorer communities and townships over problems with electricity, water, sanitation, public transport and health and education services.
Chief union negotiator Mugwena Maluleke said a mediator would now have to be appointed in the wage dispute, with talks expected to last about 30 days.
In the event of "failure to find a solution, we will hit the streets", he told a news conference.
On Tuesday, the government cancelled a news conference called to announce details of the "wage settlement" reached between the two sides. – Reuters