"In our view it would be a mistake on the part of government if it were to steam ahead on the basis of this Constitutional Court judgment and implement what we all now know to be an extremely unpopular policy," Vavi told journalists on the sidelines of Cosatu's elective conference in Midrand.
"We want to warn government: Don't even think about it," he added.
The Constitutional Court on Thursday set aside an interim order that put on hold a plan to toll highways in Gauteng, pending the outcome of a judicial review.
"The interim order granted by the high court on 28 April 2012, is set aside," said Deputy Chief Justice Dikgang Moseneke, finding that the high court had not considered the separation of powers between the court and the executive.
The North Gauteng High Court in Pretoria granted the Opposition to Urban Tolling Alliance (Outa) an interdict on April 28, ruling that a full review needed to be carried out before electronic tolling of Gauteng's highways could be put into effect.
Sanral and National Treasury appealed the court order.
Sanral argued that delays in the project, due to the court's order, prevented it from paying off debts incurred in building gantries.
Vavi was adamant that Cosatu would not let the issue rest: "The Lula moment we have adopted here and the programme of action means we will resist any attempt to toll the roads of KwaZulu-Natal, Western Cape, Gauteng or anywhere else."
"This is a national issue for us. Gauteng is just the first step."
Vavi said the union federation objected to the impact the tolls would have on the poor. "Our objection to the introduction of e-tolls in Gauteng was never based on whether it was legal or not. [We were concerned with the effect it would have on] the poor, in a manner that was to make them sidelined, and forced off the highways."
"Our mobilisiation is not over. Our message to those opposed to the tolls is don't drop your guns. We need your energy, we need your unity more than any other time before."
He would not be deterred by the Constitutional Court's ruling: "The court action is neither here nor there. It helped in delaying things. But the fact is we are opposed to the idea that the highways must be privatised and people must pay a fee to use it. This is our primary objection."
"We insist there must be an alternative solution."
A massive public outcry over tolls was supported by Cosatu, which said toll fees on a heavily-used commuter route would financially cripple the public.
The transport department welcomed the ruling.
"The ruling reaffirms government's conviction that the North Pretoria High Court had erred in its judgment which interferes with policy making, a responsibility of the executive," it said in a statement.
"Government respects the right of any member of the public to approach the courts to review its decisions and operations within the country's legal framework."
"Government remains convinced about the appropriateness of the Gauteng Freeway Improvement Project, with the user-pay principle, as part of our country's investment in road infrastructure and our collective drive to grow the economy," it said.
The government will study the judgment and make an announcement on the way forward soon. – Additional reporting by Sapa and Verashni Pillay