How well does online retailer Amazon treat its workers? Conditions in the company's giant warehouses have been condemned by unions as among the worst in Britain.

It's the online retailer that has transformed the way we shop, but how does Amazon treat the workers who retrieve our orders? Working conditions in the company's giant warehouses have been condemned by unions as among the worst in Britain. Panorama goes undercover to find out what happens after we fill our online shopping basket.