Up to 4,000 workers struck at 373 Crown Post Offices for half a day on Friday afternoon of last week.
They are members of the CWU union. The strike was over pay, closures and job security.
“I think we need a gigantic demonstration,” said Linda, a worker at the Saint Vincent Street branch in Glasgow.
“We’ve had three years pay freeze then 1.4 percent for one year and now we’re being told to accept three more years pay freeze.”