"We have communicated that members must go back to work. At the current moment I'm still waiting for feedback as to whether all workers are back at work," Numsa general secretary Irvin Jim said.
He said employers had fulfilled their obligation, as stipulated in the project labour agreement.
On Monday the Numsa and contractors at the Eskom power station reached a resolution on the agreement, ending a strike that lasted almost four weeks and halted construction at the power plant.
Workers had queried the way their year-end bonuses had been calculated, claiming this should have been done on the basis of a six-day week, not a five-day week.
Workers also did not agree with the project labour agreement, complaining that employees who lived in the area were paid less than workers who came in from Johannesburg. On Tuesday afternoon workers went back on strike after employers failed to deliver on the obligations stipulated in the agreement.
'Arrest' poor industrial relations
Jim said part of the agreement to end the strike was that workers should get a once-off payment of R2 000, plus a month's salary. They would also get an interest-free loan to the value of 90 hours of work, which workers would pay back over six months.
Some of the workers were paid on Tuesday, but others were not. Jim said employers had since paid the R2 000 to workers. They were expected to return to work immediately.
"The other part of the agreement is that we would then sit down under Eskom facilitation to negotiate all issues related to project labour agreement, and that employers would give results of the bonuses that were calculated wrongly after auditing has been finished," said Jim.
He said the union hoped to "arrest" the poor industrial relations at the power station.
Comment from Eskom could not be immediately obtained. – Sapa