The fast-fashion company Shein is stepping up preparations for a London listing after its attempt to float in New York faced regulatory hurdles and pushback from US lawmakers, sources have told Reuters. The online clothing retailer plans to update China’s securities regulator on the change of the initial public offering (IPO) venue and file with the London Stock Exchange (LSE) as soon as this month, said one source. Shein, which according to one of the sources was valued at $66bn (£52bn) in a fundraising last year, started engaging with the London-based financial and legal advisers to explore a listing early this year, said the source and a separate person familiar with the matter. The fashion company, which was founded in China but is now based in Singapore, has also approached London-based fund managers for introductory meetings before the planned float, another source with direct knowledge of the matter said. Shein and the LSE declined to comment. The China Securities Regulatory Commission (CSRC) did not respond to a request for comment. Shein confidentially filed for an IPO with the US Securities and Exchange Commission (SEC) in November, and approached the CSRC to seek Beijing’s approval in the same month, sources have said. The plan for a US IPO is still officially on the table, but the Singapore-based company has been struggling to clear regulatory hurdles in the US and China, amid criticism from US lawmakers over alleged labour malpractices and lawsuits from competitors. The CSRC earlier this year told Shein that the regulator would not recommend a US IPO due to the firm’s supply chain problems, said a separate source. While Shein is now gearing up for a London float, it still prefers New York as its listing venue and plans to keep its SEC application alive in case there is a change in the stance of US regulators, said the second source. It may also pursue a secondary US listing in New York after its London IPO when it deems the US political climate more favourable, the second source added. Republican senator Marco Rubio in February asked the SEC to block Shein’s attempt to list publicly in New York unless the online retailer makes additional disclosures about its business operations and “the serious risks of doing business” in China. The company has faced tougher-than-expected scrutiny from US regulators in an election year. In a sign of the fraught nature of the application process, the SEC has yet to advance Shein’s IPO filing, said the two sources. The SEC did not respond to a request for comment. The IPO, if it materialises, could be one of the largest globally this year, sources have said. For London, it could mark a turnaround after companies such as UK chip designer Arm chose to list in New York to chase more liquidity. Of the 30 IPOs in Europe so far this year, only four have taken place in London.