Electricity utility Eskom and its trade unions were expected to meet on Monday to discuss a wage dispute that could see workers go on strike.
Unions have rejected an 8% wage offer increase and a once-off bonus of 1% of their salary.
The parties involved in the salary negotiations were expected to meet at the Commission for Conciliation, Mediation and Arbitration (CCMA) on Monday to find out if Eskom had revised its offer.
"If there is no movement from Eskom, the Commissioner will issue a non-resolution certificate.... but whatever the situation is, we will have to go back to our members and they will decide what the next step will be," Solidarity spokesperson Dirk Hermann said on Friday.
The unions involved are Solidarity, the National Union of Mineworkers and the National Union of Metalworkers of South Africa.
The CCMA issued a statement on Friday to say that no deadlock had been reached yet and that mediation was ongoing.
Unions were demanding a 15% increase and a R5 000 per month housing subsidy.