If their demands are not met, the "mother of all strikes" will start at South African Airways (SAA) and SAA Technical on Friday morning, unions warned at a media briefing in Johannesburg on Wednesday. 

The National Union of Metalworkers of South Africa (Numsa) and the South African Cabin Crew Association (SACCA) said the strike would begin a 4am on Friday morning. Earlier on Wednesday SAA leadership confirmed it had received a strike notice. 

According to the unions, who say they represent more than 3 000 workers at the airline, a 48-hour notice to strike has been submitted. Cabin crew, check-in staff and technical staff will be involved.

The unions suggested that members of the public who are set to travel on SAA from that date make alternative arrangements, as the strike will likely cause disruptions. 

The unions and the struggling state-owned airline are deadlocked over the demand of an 8% across-the-board wage increase. Unions also want to have job security for at least three years and the insourcing of services like security, cleaning and ground handling. 

According to Numsa and SACCA, SAA pilots recently received a 5.9% increase. The two unions said their members were simply demanding increases as well, which should be higher than pilots as they earn less.

SAA announced on Monday that it is embarking on a restructuring process which may affect 944 jobs - almost a fifth of its employees. The restructuring excludes SAA subsidiaries SAA Technical, Mango Airlines and Air Chefs.

Numsa general secretary Irvin Jim said at the briefing on Wednesday that he regards the retrenchment notice by the airline as a "decoy".

"We are grounding that airline on Friday. It must not move. This is an indefinite strike. If they think we are playing, they have got it coming."

He did add later that the unions are still open for discussions with SAA management before the strike commences. 

Jim said Numsa will approach the South African Federation of Trade Unions to see if the SAA strike can be expanded to a wider basis. "We are sick of investment conferences. Workers must now turn to the state and demand that it intervenes in the economy."

Deon Fredericks, the interim chief financial officer of SAA, said at a media briefing on Tuesday afternoon that any industrial action would endanger the existence of South African Airways, and could destroy every job at the state-owned airline as well as related industries.

Fin24 understands that SAA is currently under pressure to secure R2-billion in working capital, which it needs before November 20, which may have is added impetus to the restructuring.

Government has said it does not want to extend further support to state-owned entities. Finance minister Tito Mboweni announced last month that any further financing will be in the form of loans, that will have to be repaid with interest. Over the past 13 years, the flag carrier has incurred over R28-billion in cumulative losses.