An attempt by Numsa to have Cosatu general secretary Zwelinzima Vavi's suspension overturned was postponed on Tuesday after the High Court in Johannesburg allowed an application by seven opposing unions to intervene.

Addressing the unions present in court, Craig Watt-Pringle SC, for the intervening unions, said it had been agreed that the application be postponed indefinitely to allow the Congress of SA Trade Unions (Cosatu) affiliates to file affidavits.

"The intervening unions have been allowed to intervene. The matter is likely to be set down for October 8," he said.

The intervening unions are the National Union of Mineworkers, the South African Democratic Teachers' Union, the Police and Prisons Civil Rights Union, the South African Transport and Allied Workers' Union, the National Education, Health and Allied Workers' Union, the Finance Union, and the Chemical, Energy, Paper, Printing, Wood and Allied Workers' Union.

The are all Cosatu affiliates, and are opposing the application by the National Union of Metalworkers of South Africa (Numsa).

Numsa is expected to file an opposing affidavit by October 2.

The Food and Allied Workers' Union and the South African Football Players' Union are listed as co-applicants in Numsa's court action. All three unions are also Cosatu affiliates.

Karel Tip SC, for Cosatu, said its central executive committee (CEC) meeting, held on Monday, could "influence what might happen in the case".

Tip did not want to elaborate and said he was speaking to his clients to inform them what happened.

In court papers, Numsa called Vavi's suspension "unconstitutional and unprecedented".

Vavi was suspended last month for bringing Cosatu into disrepute after he admitted to having an affair with an employee.

Numsa general secretary Irvin Jim said Cosatu had stated it was not ready to proceed with the matter.

"Being a democratic union, we took a firm view that it would be wrong and unfair to try for this matter to be heard without them having prepared for the case," Jim said outside court.

"Therefore, the case has been postponed by agreement," he said.

He said Numsa had decided to go to court to ensure Cosatu continued to be the voice of workers. This was a matter of principle, he said.

"Cosatu is not made up of seven affiliates, so we are very relaxed. The federation belongs to workers.".

There are 21 unions within Cosatu.

Cosatu president Sidumo Dlamini said the intervening unions believed the decision to suspend Vavi was made at Cosatu's CEC and should, therefore, stand and not be contested in court, he said.

"Being the majority or minority does not count. What counts most is a Cosatu that ought to be united at all material times," Dlamini said.

"An opportunity has been availed for us. We need to take it with both hands to see whether we can resolve matters outside the court. It's not about stopping the [court] process it's about finding amicable solutions."

Vavi's disciplinary action was continuing and it was not known when the process would be completed, he said.

There was no sign of Vavi at court on Tuesday morning.

After the hearing, a group of Numsa supporters gathered outside the court building and sang songs before Jim addressed them.