The supermarket, meanwhile, has claimed "customers are choosing not to support the pickets"
Trade union Mandate has claimed Tesco Ireland stores affected by strike action are experiencing "an average loss in sales of over 80%" - while the supermarket itself has reported "high volumes of customers" over the weekend.
Strike action is currently underway at 16 Tesco stores around the country, in a row over proposed contract changes for workers who were employed before 1996.
Mandate claims the supermarket is trying to force long-serving staff to accept poorer contracts.
Tesco, meanwhile, has argued that the terms of the contracts mean they have too many people working during the earlier, quieter times of the week.
Workers in a further 23 Tesco stores will be balloted to join the dispute this week.
Tesco has acknowledged that numbers were 'down on normal trade' over the weekend at the 16 impacted stores, but says the stores still received 45,000 customers.
"Such high volumes of customers serves as a positive reinforcement that customers are choosing not to support the pickets and continue to shop with us," the company said in a statement this afternoon.
"Support on the picket lines dwindled across the weekend too, with numbers having to be inflated by non-Tesco workers in all locations. The reality is the strike has not been supported in the way Mandate expected by employees or customers," the statement also claims.
The company has reiterated its call by Mandate to accept Labour Court recommendations on the dispute.
Mandate, meanwhile, has accused Tesco of failing to respond to proposals tabled by the union during talks last week - and expressed "its disbelief and disappointment" at the lack of response.
The union says acceptance of the proposals would see an immediate suspension of the industrial action.
John Douglas, Mandate General Secretary, said: "Such a lack of urgency and unwillingness to engage raises the legitimate question as to whether the company really wants to find a resolution to the current dispute or is there a bigger and more significant objective they are trying to achieve on the back of the pre-‘96 contract dispute."
“Contrary to what Tesco Ireland have been spinning, most impacted stores are experiencing an average loss in sales of over 80%," he added.