The Freedom Front Plus said the government's e-toll consultation process was merely a 'smoke-screen' to gather support for the system.

"The FF Plus... [is] advising motorists not to go and purchase e-tags until the review of the e-toll system has been concluded in the Johannesburg High Court," MP Anton Alberts said in a statement.

"Legislation and regulations [for e-toll implementation]... still have to pass through Parliament."

The government said there would be a 30-day period for public comment.

"Government will, at the end of 30 days, incorporate this round of public comment and publish its final position after a further 14 days," it said.

The Democratic Alliance said the public had to be aware that lower Gauteng e-toll tariffs could always be raised later.

"It's no use 'sweetening' the e-tolls by lowering the tariffs, as they can always be raised later," DA Gauteng MPL Jack Bloom said in a statement.

"Lower tariffs also make the e-toll collection even more irrational, as we could end up spending more on the collection system than on the roads."

Bloom said it was unfair to call for public comment without making the e-toll contract available.