STORY: Shein looks to be headed for a share sale in London.

Two Reuters sources say that's now the plan, amid stumbling blocks to a listing in the U.S.

The fast-fashion giant has faced regulatory hurdles and pushback from lawmakers in Washington over alleged labor malpractices.

Instead, one of the sources says Shein will file for a listing on the London Stock Exchange as soon as this month.

One source says it was valued at $66 billion in a funding round last year.

That means any IPO could potentially be one of the year's biggest and a coup for London, which has been struggling to attract big names.

There was no comment on the Reuters report from Shein or stock exchange officials.

Meanwhile, the plan for a New York listing is still officially active.

But a separate source says Chinese regulators have warned Shein against the move, due to the controversy over its supply chain.

The firm reportedly still prefers New York as a listing location, and is watching for a change of stance by U.S. watchdogs.

One option is said to be a secondary listing in the city some time after London, if and when the U.S. political climate grows more favorable.