The Congress of South African Trade Unions (Cosatu) in the Western Cape said farmworkers are growing increasingly frustrated that their demands for better wages have not yet been met.
Mass meetings were held in De Doorns, Ashton and Villiersdorp on Sunday.
Last month, an illegal strike was marred by violence in several farming areas in the cape.
After talks with the trade union federation, workers agreed to suspend their strike over wages and better living conditions for two weeks.
The suspension was on condition that the wage determination for agriculture, a minimum wage of R70, be cancelled and renegotiated by the Employment Condition Commission.
It is feared labourers will down tools again tomorrow.
“As a result of there being no offer, the workers have decided that the strike that they suspended two weeks ago will continue on Tuesday 4 December, said Cosatu Western Cape Secretary Tony Ehrenreich.
“We could see a nationwide strike because of the attitude of farmers,” he added.
Ehrenreich said wage negotiations between farmworkers and farmers' associations, to be paid R150 daily, were ongoing.
He said an announcement would be made if a deal was agreed upon by the end of Monday, but that strike action would resume if that was not the case.
Police said they were prepared for any eventuality on Tuesday.