"Although the e-tolling tariff was just reduced by Minister [Pravin] Gordhan, and although taxis and buses are exempted, the very principle of privatising our roads is something Numsa firmly opposes," the national executive committee said in a statement on Saturday.

"On March 7, 2012, we will turn to mass street power to exert pressure for a total ban on labour broking, and for the scrapping of the privatised e-tolling system in [the] Gauteng province."

Government spokesman Jimmy Manyi said earlier this week that Gauteng toll fees were set to become a fact of life and the law and the government will tolerate no disobedience.

With effect from April 30, motorcycles with e-tags would pay 20 cents a kilometre and those without, 38 cents.

Light motor vehicles would pay 30 cents and 58 cents respectively, and non-articulated trucks 75 cents and R1.45.

Articulated trucks with e-tags would pay R1.51 a kilometre and those without R2.90.