The Department of Public Service and Administration says the Public Servants Association (PSA) strike is unprocedural.
The PSA is set to go ahead with its strike on Monday, although other unions in the sector, representing more than 65% of the workers, have signed the wage deal.
Nehawu, SAMA, Denosa, Pawusa, Popcru and Sadtu accepted government’s offer of a 7% wage increase on Friday.
Sadtu General Secretary Mugwena Maluleke has complained of the role of global ratings agencies.
“We would like to put on record that these negotiations were the most challenging. Government auctioned the power to negotiate to the rating agencies who seem to influence indirectly the negotiations towards a particular outcome through threats of downgrades, as these higher than expected wage settlements could add to the debt burden.”