The Congress of SA Trade Unions has more "creative-ways" to make the e-tolling system an epic failure, general secretary Zwelinzima Vavi said on Tuesday.
He told reporters in Pretoria if government went ahead with e-tolling on Gauteng freeways after Wednesday's strike, Cosatu would organise more strikes.
The nationwide strike is in protest against e-tolling and labour broking.
"Particularly on April 28...we are more likely to think about lots of creative ways which we have talked about which will make that whole [e-tolling] system unworkable...completely unworkable."
He said government would have to choose between the economy losing billions in the e-tolling battle or choose to negotiate with the organisation instead.
"Government has R300 billion, it can't tell us that it can't get just R20 billion from that R300 billion to pay for public roads," he said.
Vavi said Wednesday's strike action was a sign that Cosatu was still willing to negotiate with government regarding the two issues.
"We are going to be listening very carefully in terms of what government is going to be saying...we are forcing government back to the negotiating table we are saying we remain open to talks, even at this moment," he said.
He said strike action was being used sparingly as it was a huge sacrifice for workers to lose a days' wages.
He said teachers were also expected to participate in the strike.
"Teachers are workers too and they have the same rights as all other workers."
He said plans would have to be put in place to make up for the learning hours which would be lost on Wednesday.
Everybody and all organisations were welcome to participate in the strike except for those working in essential services.
Cosatu said it would not allow participating political parties to push their own agendas at the strike.
He said the attendance of ANC Youth League leader Julius Malema was placing Cosatu in a "tight corner".
Malema was in solidarity with the action and would march with protesters on Wednesday, said Vavi.
A total of 34 marches will be taking place across the country.
In Johannesburg protesters were expected to gather at the Library Gardens and proceed to the department of labour and then the department of transport.
MORE WAYS IN STORE TO HALT TOLLS: VAVI