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.

Eskom workers have carried the burden of keeping the grid stable and their livelihoods must be protected, it adds.

The NUM NEC rejects any asset separation undertaken without full consent and consultation with organised labour, the union says.

The union's NEC also demands explicit guarantees from government that no workers will lose their job or suffer degraded employment conditions as a result of these reforms.

“The NEC unequivocally rejects the gradual privatisation and liberalisation of South Africa's electricity grid. Electricity remains a strategic national asset.

“We call on government to halt all steps toward market liberalisation until a comprehensive social compact is reached with labour and key stakeholders,” the NUM says.

In addition to the legal proceedings, should government continue to proceed with reforms that threaten public ownership, undermine Eskom's strategic mandate or compromise workers' rights without genuine consultation, the NEC stands ready to deploy all available constitutional and organisational measures, including worker mobilisation, to defend energy sovereignty, public ownership and workers' livelihoods, it says.

As the ERTT enters Phase II to finalise an implementation plan over the next three months, the NUM NEC demands full and meaningful consultation at every stage.

Sector reforms must strictly adhere to Just Transition principles, namely prioritising energy security, affordable power, industrial growth, localisation and the public interest above private profit, the union says.

Further, the NUM NEC welcomes the ERTT Phase I Report's recognition that mounting municipal debt severely threatens Eskom's financial sustainability.

Government must prioritise resolving municipal debt, improving revenue collection, and strengthening core governance before implementing structural changes that risk operational stability and create worker uncertainty, the NUM says.

Meanwhile, expansion of South Africa's electricity transmission and distribution grid has not kept pace for many years.

NTCSA CEO Monde Bala last week told delegates attending the South Africa-China Electricity & Energy Investment Conference, in Beijing, China, that priority transmission expansion projects represented a R134-billion investment opportunity, within a broader R440-billion decade-long programme.

The Transmission Development Plan programme is targeting the construction of about 14 500 km of new transmission lines by 2034 and the installation of about 133 000 MVA of transformer capacity.

Bala said the NTCSA did not have the capacity to fully execute the rollout of the necessary infrastructure on its own.