Sir Sadiq Khan has been urged to ban all advertising from fast-fashion giant Shein on Transport for London’s (TfL) network, amid concerns over the firm’s human rights record.

The retailer, founded in China but now headquartered in Singapore, has been criticised over its environmental impact and working practices, which include allegations of forced labour in supply chains.

The mayor’s office referred the BBC to TfL, which said it would issue a response to London Assembly Green group leader Caroline Russell, who says TfL’s acceptance of advertising revenue puts “profits before human rights and dignity”.

The assembly member’s concerns were raised in the same week that the campaign group Stop Uyghur Genocide launched a judicial review to prevent Shein’s Initial Public Offering (IPO) listing on the London Stock Exchange.

“As you will be aware, Shein was one of the companies questioned on labour standards in their supply chain by parliament’s business and trade committee in early January,” Russell told Sir Sadiq in a letter released on Thursday.

She said Shein representatives failed to answer the committee’s question over the use of cotton sourced from China’s Xinjiang region “which is notorious for the forced labour of the minority Muslim Uyghur people”.