The independent trade unions collective comprising six affiliates called the demonstration.
TU leader Sugath Rajapakse said around 3,000 workers took part, while more were to join.
But, employers refused to end the 4.00 pm work shift, and a large number missed it, he said.
Workers would come forward stronger if employers continue to repress them, he warned.
FTZ worker Gayan Pradeep said he was threatened by thugs and was subsequently suspended for having tried to form a trade union.
Increase in sexual bribes
During the protest campaign, female workers alleged there has been an increase in the incidence of employers’ soliciting sexual bribes from them.
TU leader Anton Marcus alleged workers were yet to be paid the Rs. 2,000 pay hike approved by the government, as some of the factory owners at Katunayake FTZ were politicians’ relatives.
He warned the government that despite human rights being guaranteed, GSP plus export concession would be lost if it did not ensure workers’ right. BBC Sandeshaya reports.