What is being looked at now is the rates, how much people are going to pay, who is going to be exempted and so on.

Cabinet has called on all government institutions to register their vehicles for e-tolling, Minister in the Presidency Collins Chabane said.

Chabane defended the decision to issue the order despite the electronic toll project being on hold pending a ruling by the High Court in Pretoria on the latest legal challenge against its implementation.

"What is being debated now is not whether e-tolling is going ahead or not going ahead. The Constitutional Court has said government has a right to proceed," he told a briefing on Cabinet's fortnightly meeting.

"What is being looked at now is the rates, how much people are going to pay, who is going to be exempted and so on.

"Government departments, municipalities, parastatals, they will have to register because government has taken a decision that they must register and once they register, and tariffs have been agreed on, payment will then start."

The Opposition to Urban Tolling Alliance (Outa), a civic rights group, has brought a court application to have the e-toll project scrapped, but a ruling has yet to be made.

The High Court in Pretoria has reserved judgment following Outa's legal challenge which argued that the system was irrational, unreasonable and illegal.

Outa wants the court to review and set aside the SA National Roads Agency Limited's (Sanral) decision to declare sections of Gauteng's freeways as toll roads to recover the costs of the Gauteng Freeway Improvement Project.

In September, the Constitutional Court set aside an interim order by the High Court in Pretoria which placed the e-tolling project on hold.

On Thursday, protest action against the toll system continued on highways in Gauteng.