Activists have launched a campaign accusing firms of “bolstering and benefiting” from exploitation of the Muslim minority group.
The US has also ramped up economic pressure, warning firms against doing business in Xinjiang due to the abuses.
Nike and other brands have said they are tracking the issue.
Nike said it was “conducting ongoing diligence with our suppliers in China to identify and assess potential risks related to employment of Uighur or other ethnic minorities”.
It said it does not source materials directly from Xinjiang, the region in western China that is home to much of the country’s Uighur population and many of the factories said to use the labour.
Apple also said it had investigated the claims. “We have found no evidence of any forced labour on Apple production lines and we plan to continue monitoring,” the firm said.
Politicians and activists say companies need to do more if they do not want to be complicit in the Chinese government’s human rights abuses.
“Brands and retailers should have left long ago, but they haven’t and that is why this public call to action is important and necessary,” said Chloe Cranston of Anti-Slavery International, one of the more than 180 organisations involved in the pressure campaign.
“It’s not just about ending a relationship with one supplier. It’s really about taking a comprehensive approach.”