A British politician said he had “almost zero confidence” in the integrity of Shein’s supply chain following a heated exchange with a representative of the fast-fashion retailer in London.

Liam Byrne, who chairs the UK parliament’s Business and Trade Committee, told Shein’s general counsel for EMEA that he was “pretty horrified by the lack of evidence that you have provided.”

The fast-fashion company, founded in China and headquartered in Singapore, may seek a UK listing in what could be one of the biggest IPOs in London this year. The company was asked to give evidence, alongside rival Temu, about its working practices to members of parliament and sent Yinan Zhu, general counsel for EMEA.

After declining to answer a number of questions, such as whether cotton from China’s Xinjiang region appears in items it sells, Byrne accused Zhu of almost bordering on contempt of parliament.

“You’ve given us almost zero confidence in the integrity of your supply chains. You can’t even tell us what your products are made from,” he said. “You can’t tell us much about the conditions which workers have to work in.”

A Bloomberg study in 2022 found that garments shipped to the US by Shein were made with cotton from Xinjiang, where the US State Department has alleged human rights abuses against ethnic minorities, which China denies.

“I don’t think it’s our place to have a geopolitical debate,” said Zhu when asked whether the company fears there is forced labor in Xinjiang.

She said the online retailer is compliant with all relevant UK laws.

Shein confidentially filed papers last year for a proposed IPO, and a listing still needs regulatory nods in the UK and China. An offering could value the company at about £50 billion ($62.4 billion), Bloomberg reported in June.

Shein, as required under the UK’s Modern Slavery Act, has published a statement outlining steps taken to ensure slavery and trafficking don’t happen within its operations or supply chain.

At the same hearing, Tesco Plc’s quality director, Claire Lorains, said Britain risks becoming a “dumping ground” for second class goods if it doesn’t reform its labor standards to bring them into line with Europe and the US.

Earlier on, the chief executive officer of McDonald’s Corp. for the UK & Ireland blamed inappropriate workplace behavior at the restaurant chain on the wrongdoing of individuals. Hundreds of current and former staff are taking legal steps against the company over alleged harassment.

“This isn’t an issue about imbalance of power” in the workplace, Alistair Macrow told MPs at the hearing on employment rights. “This is about very poor behavior from individuals in the organization.” 

Some 700 people who were 19 and younger when working at the restaurant chain instructed Leigh Day to take legal action against McDonald’s on their behalf, the law firm said in a statement.