Johannesburg - The Labour Court in Johannesburg turned down an urgent application by the National Union of Mineworkers (Num) on Monday to stop Eskom from implementing a 7% unilateral wage increase.
The court ruled that the application did not satisfy the requirements of an interdict. The application was dismissed with costs.
Num is expected to apply for leave to appeal.
"We are very disappointed... this has never happened in Eskom. It might set a precedent," Num energy sector coordinator Job Matsepe said.
"We are open for negotiations... but it seems unions have no place in Eskom."
Wage talks with Num, the National Union of Metalworkers of SA (Numsa) and Solidarity recently deadlocked. The unions demanded a 13% increment, but Eskom's last offer was 7%.
The Labour Court's decision shows it is aligned with the interests of big capital, the World Federation of Trade Unions said.
"The WFTU supports the National Union of Mineworkers' charter of demands, among them the salary increase of 13%, and we denounce the court decision," the Athens-based federation said.
"We extend militant support and solidarity greeting with your struggle against Eskom, in courts, in the streets of struggle and wherever is necessary."
The Federation, with a membership of 82 million members, said it supported the fight for the rights of workers both in the sector and the working class in South Africa. One of these rights was "stable salaries and increases...that correspond with contemporary workers' needs."