National Union of Metalworkers of SA (Numsa) general secretary Irvin Jim confirmed on Monday that the application would be heard.
In court papers, Numsa called Vavi’s suspension “unconstitutional and unprecedented”.
Earlier this month, Jim said the union had been forced to take legal action as “Cosatu’s internal and democratic processes are being undermined and flouted”.
He said the decision to legally challenge the Congress of SA Trade Unions (Cosatu) had not been made lightly, and it was not the preferred option of engagement after delegates called for Vavi’s suspension in the February and May central executive committee meetings.
The Food and Allied Workers’ Union and the SA Football Players’ Union are listed as co-applicants in Numsa’s court action.
Vavi was suspended last month for bringing Cosatu into disrepute after he admitted to having an affair with an employee.
Cosatu spokesman Patrick Craven confirmed that it had been served with the court papers.