(NewsNation) — Fast-fashion behemoth Shein has tried to become a member of the largest retail trade association in the U.S. in its quest to go public on the American market, but it has been rejected repeatedly as geopolitical tensions and labor controversies persist.

Despite grossing billions in sales every year, the National Retail Federation has continually denied the Chinese-owned brand membership, which would help legitimize the fashion brand in the U.S.

Julie Zerbo, an expert on fashion and law, joined “NewsNation Now” to discuss what this roadblock means for Shein, saying it is likely due to the continued backlash over its controversial labor practices.

“It is a reflection, I think, of a broader issue for retailers across the board. As their supply chains have become increasingly complex, increasingly multinational and increasingly reliant on third-party suppliers, it’s really difficult for even well-meaning companies to say with certainty whether or not their suppliers are abiding by labor laws in any of these countries,” Zerbo said.

For most companies, joining the NRF wouldn’t have a major impact on their business, but Shein has been working to convince lawmakers that it can be trusted as a public company listed on American exchanges despite concerns over its ties to China.

“They’re certainly setting themselves up for options, including in London. … I think Shein, it might be possible, but they certainly have a lot of work to do in light of the really rampant skepticism amongst U.S. lawmakers ahead of this potential IPO,” Zerbo told NewsNation, citing Alibaba as another Chinese company that went public after some controversy.

Shein was recently valued at $66 billion, according to CNBC, and is poised to become one of the biggest listings of the year.

The NRF hasn’t totally shut the door to Shein’s membership application and has been in talks with the retailer about its request, people familiar with the dynamic said.