LONDON, Dec 12 (Reuters) – Britain’s financial regulator is taking longer than usual to approve fast-fashion retailer Shein’s IPO because it is checking its supply chain oversight and assessing legal risks after an advocacy group for China’s Uyghur population challenged the listing, according to two sources close to the matter.

Britain’s Independent Anti-Slavery Commissioner, a monitoring body of the interior ministry, has also raised concerns within government over a Shein IPO because of allegations about labour practices at its suppliers.