Nine Cosatu-affiliated unions have reinstated their court case to compel the trade union federation to hold a special national congress, they said on Wednesday.

"We have reinstated our court case... as the crisis can clearly only be resolved by owners of the federation – the ordinary members of affiliates of Cosatu," Food and Allied Workers' Union (Fawu) deputy general secretary Moleko Phakedi told reporters in Johannesburg, on behalf of the unions.

"We reject any moves at dismissing [general secretary Zwelinzima] Vavi from Cosatu. A special congress must attend to all the matters now raised against him."

An application by the National Union of Metalworkers of South Africa (Numsa) for an urgent interdict to stop the Congress of South African Trade Unions (Cosatu) holding its central executive committee (CEC) meeting on Friday, will be heard in the High Court in Johannesburg on Thursday.

The unions said the CEC would likely decide to expel Numsa at the meeting so it could "smoothly" deal with Vavi.

Numsa deputy general secretary Karl Cloete said the application was urgent.

"It is an urgent court application... to the extent the court says it is not urgent we will proceed on that basis," he said.

"We hear that if the court were to move in that direction we are likely to get the matter on the roll for March 2015. So be it, we go to March 2015.

"We have a case to make that Cosatu has been turned into a tavern with no rules."

The unions included Numsa, Fawu, the South African Catering, Commercial and Allied Workers' Union, the Democratic Nursing Organisation of South Africa (Denosa) the South African State and Allied Workers' Union, the Communication Workers' Union, the South African Football Players' Union, and the Public and Allied Workers' Union of South Africa.

Cloete said the South African Municipal Workers' Union (Samwu) was currently appealing a high court ruling that expulsions and suspensions in the union were unlawful.

"There is an appeal against that judgment. What we can say is that we have nothing whatsoever from Samwu in writing or verbally that it is not part and parcel of the nine unions that have petitioned for the special national congress."

Numsa and Cosatu have been at loggerheads since the trade union federation suspended Vavi. This was after a junior colleague alleged he had raped her at work. She had not reported it to police. Vavi said they had an affair.

Numsa supported Vavi during his suspension and instituted the court proceedings against Cosatu, insisting Vavi be reinstated.

At its special congress in December, Numsa decided not to support the African National Congress during the general elections.

Cloete said on Wednesday there was no reason why Numsa would not attend the CEC meeting if it were to be held.

"We have every intention, like we have done in the last, to put forward our positions as it is in line with the Cosatu constitution," he said.

"The court case is about asking the court to rescue all of us in Cosatu with respect to the violation of the Cosatu constitution all the time."

Cloete said the nine unions collectively represented 983 116 members. Because of the loss of members from the National Union of Mineworkers, Cosatu's collective figure of 2.2-million members would have to be revised.

The unions said one of the reasons why a faction in Cosatu wanted Numsa expelled was because it had decided to "extend its scope".

They said this was prevalent in other affiliates where nursing unions organised transport workers, such as ambulance drivers, and mining unions organised cooks, such as those who worked in mine canteens.

Cloete used the example of Cosatu president Sidumo Dlamini, who was a nurse.

"The Cosatu president is a nurse but belongs to Nehawu [National Health and Allied Workers' Union] when there is Denosa. This must tell you something."

Numsa president Andrew Chirwa said: "Those who say no to a special congress are the first who are running from workers... the CEC of Cosatu is incapable of dealing with the future of Cosatu."

He said Numsa "was there" in 1985 when the federation was formed.

"Numsa owns as well an intellectual property of Cosatu, in particular the workers in Numsa."