Johannesburg - The Federation of Unions of SA (Fedusa) will join Cosatu's strike notice over the Gauteng tolling system, it said on Tuesday.
"The open road tolling system is aimed at consolidating the privatisation of our national roads and this simply cannot be allowed to happen," said Fedusa general secretary Dennis George in a statement.
Earlier this year, Cosatu submitted a Section 77 or strike notice to the National Economic Development and Labour Council over the toll tariffs.
He expressed concern that the proper consultation over the tolling tariffs had not yet taken place.
In February, Transport Minister Sibusiso Ndebele, appointed a committee to look into the tariffs after a public outcry over their effect on the economy and people's pockets.
"Government cannot forgo their responsibility of maintaining the country's infrastructure and then unilaterally decide to pass on these costs to taxpayers, consultation with the social partners must be made a priority," said George.
Earlier this month, the committee came up with a proposal which saw the tariffs reduced.
According to the proposals, users of light motor vehicles would pay R0.40/km instead of R0.49/km, minibus taxi drivers R0.11/km instead of R0.16/km and bikers R0.24 instead of R0.30/km.
This only apply to people using e-tags. The initial tariff announced was R0.66/km for vehicles without an e-tag account.
For medium vehicles, the toll fee was reduced from R1.49/km to R1 and for large vehicles from R2.97 to R2. For commuter buses the cost would be reduced from R0.50/km to R0.36.
An e-tag works much like pre-paid cellphone airtime, fits on the front windscreen of a vehicle and is scanned by toll gantries.
Forty two electronic toll gates have been erected on the N1, N3, N12, N17, R21 and R24. The tolls cover a distance of about 185km.
Cosatu remained unhappy about the toll tariffs.
The SA Municipal Workers' Union, a Cosatu affiliate, said the tolls would impose a huge additional burden on road users. It would have a devastating effect on workers who had no alternative but to drive to work because of a lack of proper public transport.