"We have noted how workers continue to be brutalised and arrested on the basis of pure labour disputes," Popcru said in a statement on Wednesday.
Popcru said the country's constitution provided for freedom of association and organisational rights.
It supported Saccawu's demands for a R3 500 minimum wage for Dis-Chem workers, plus a 15% across-the-board increase.
Popcru also believed that casual workers at Dis-Chem should become part of the group's permanent staff after three months of service.
A 13th cheque should be guaranteed as well as parental rights, medical aid, housing subsidies and long service awards, Popcru said.
Two thousand Saccawu members employed at Dis-Chem have been on strike for over a month.
Last week a burning gas canister was thrown into an Olympus Dis-Chem store in Faerie Glen in Pretoria, and the store has been closed for repairs.
Three Dis-Chem workers have been arrested for malicious damage to property.
Dis-Chem human resources manager Johan Ochse was not available for comment.
- Sapa