Boohoo's facing the possibility of its clothes - and those made by its suppliers - being banned from the US.
Authorities there are considering a petition by a British lawyer who claims the retailer's not doing enough to stop forced labour in factories in Leicester.
Duncan Jepson, who also runs Liberty Shared, started the petition and wants people to "wake up":
"What... we'd all like is for Boohoo is to really get to grips with the governance of their supply chain", he said.
"To ensure that there's no wage theft, to ensure that people have proper contracts."
Boohoo says it's working closely with enforcement bodies - and investigators have found no evidence of modern-day slavery.