The construction of the Medupi power station in Lephalale, Limpopo, could be plunged into turmoil if the company does not accede to workers' demands to reverse its decision to dismiss them.
The workers had initially threatened to stop doing overtime work after complaining of "serious problems" with the food provided to them.
The construction of the station is estimated at a cost of more than R450billion.
The Medupi Fabrication, a company subcontracted to Eskom, suspended 206 workers on March 11 after they embarked on an "illegal" strike, refusing to work overtime. The workers were subjected to a disciplinary hearing.
But the Building Construction and Allied Workers' Union said the manner in which the matter was handled by the company was unprocedural.
The company allegedly refused to accept the hearing was flawed and proceeded with it.
The hearing was concluded on March 16 and the union requested that in terms of the project labour agreement the company provide the outcome of the hearing within five working days. The company has allegedly failed to do so.
Union organiser Albert Masuku told Sowetan yesterday they regarded the hearing as "unbinding" because of the manner in which it was handled.
But the company allegedly refused to recognise the decisionmade by an arbitrator. On March 29, the employees were given dismissal letters.
Masuku said they would embark on a national strike if management did not reverse its decision.
"We are aware our action might lead to a delay in the construction of the station but we also want our members to be treated fairly," he said.