Labour union the National Union of Mineworkers (NUM) says its legal team is preparing to take formal court action to challenge the decision to establish an independent transmission system operator (TSO).

President Cyril Ramaphosa approved the Eskom Restructuring Task Team (ERTT) Phase I Report on July 31.

The NUM states that its national executive committee (NEC) strongly opposes transferring strategic assets, infrastructure, employees or operational functions from the National Transmission Company of South Africa (NTCSA) to a new TSO.

Transferring transmission assets away from State-owned power utility Eskom risks fragmentation, increased private sector dominance and the gradual erosion of public control, the union says.

Restructuring must not come at the expense of jobs, working conditions, collective bargaining rights or public ownership, it states.