Sut Cliff also pointed to flaws in the process, saying the relevant stakeholders had not been consulted on the matter.

"This proposal has not even been addressed by the provincial transport department," he said.

"The real stakeholders who will make the decisions regarding the road have not yet been brought into play. National government is impelled to involve local government in decisions of this nature," he said.

The SA National Roads Agency approved the development of the 540km road in June last year. The agency initially expected to start construction this year and finish the road next year.

However, fierce lobbying by environmental groups, communities and municipalities has set back the process, throwing the future of the development into doubt.

The agency is awaiting a record of decision on its environmental impact assessment from the environmental affairs and tourism department. But it could be a long wait. The department's director general, Crispian Olver, said yesterday that an independent evaluation was under way, with a decision only expected in December.

The firms involved in the toll road consortium include Group Five Construction, Grinaker-LTA, Hawkins Hawkins & Osborn, Stewart Scott, WBHO Construction, Rand Merchant Bank and Kagiso Financial Services.