Johannesburg - Nehawu on Monday accused Treasury of conducting public service wage negotiations outside the collective bargaining process.
The announcements made by the minister of finance about the wage negotiations in mini budget "are deeply worrying and are likely to compromise the negotiations," National Education, Health, and Allied Workers' Union general secretary Bereng Soke told reporters in Johannesburg.
"We urge the employer to draw lessons from the past two rounds of collective bargaining in the public service, which necessitated strikes as a result of this approach."
He said Treasury had publicly announced it was likely salaries would increase by 6.6% while negotiations were ongoing.
Presenting his first mini budget last month, Finance Minister Nhlanhla Nene said the public service would have to accept inflation-related increases, or face staff cuts.
"If increases in public-sector wages significantly outpace inflation, government will be forced to curtail service delivery - either by reducing social spending or capital budgets, or by trimming staff numbers," he said.
Nene added that civil service staff numbers would be frozen for the remainder of the medium-term framework, and that departments creating new positions would have to fund these out of their existing resources.
Last month, Nehawu called for public service wage talks to be reopened because the three-year agreement, signed in 2012, would expire in March 2015.
The union is seeking a single-term agreement with a 15% increase across the board, a R3 000 housing allowance, pending finalisation of the government employees housing scheme, and an annual subsidy adjustment for the Government Employees Medical Scheme (Gems), based on CPI.
It also wants the medical scheme's services administered internally.
Further, it wants six months maternity leave and two weeks paternity leave for civil servants, and 10 days special leave for those parents with children who have special needs.
It also wants salary levels one to three abolished.
According to the union, workers on salary level one earn around R5 650 a month, level two R6 087, level three R7 277, and level four R8 624.
Soke said Nehawu was unhappy that Treasury had announced it was planning to review vacancies.
Nehawu president Mzwandile Makwayiba said negotiations were not conducted in Parliament, and it would fight for public servants.
"If anyone wants a fight, we'll give them a fight. One thing we are not going to do, we not going to allow a situation where we are not given wages on the basis of CPI increase and real wages.
"So anyone who wants to avoid a strike in the public service must come to negotiations and really negotiate."
He said government had not come back to the union after it had submitted its demands.