What is the true cost of Asos's fast fashion? The retail giant will ship clothes to you wherever you are in the world, but only at the expense of its warehouse workers who are routinely surveilled, searched and abused.

More and more stories are coming out of Asos's packing warehouse in Barnsley, Yorkshire, where workers are advised not to drink water or take toilet breaks in the last working hour "because the last hour is very important for performance. Even 30 seconds is very important for the company." Workers at the warehouse are represented by the GMB trade union, which has been running a campaign at the site for more than a year, supporting its members outside the gates because management refuses to allow it in.

Asos is a huge name in the UK with a turnover of over £1 billion a year. It says it has safeguards in place, but clearly something has gone very wrong.

Tell Asos it can't treat its workers this way

GMB has called on Asos to recognise the union's role in representing workers at the site and to urgently address concerns over working practices, contracts, targets and surveillance. The list of concerns only gets longer.

• Workers are allegedly fired for falling ill or taking time off to care for sick relatives.
• It has been claimed that pay is docked if an employee arrives at the warehouse even a single minute late. Workers say 15 minutes pay has been docked for one minute's lateness, which takes pay down to less than minimum wage - £5.59 for 59 minutes' work.
• Staff on "annualised" hours contracts have had their shifts cancelled or extended at extreme short notice - as short as 3 hours.

Alongside the poor treatment of staff, the company uses outsourcing group Transline to recruit staff for the factory - Transline uses complex payment schemes to avoid a huge amount of tax.

We've moved Asos before. In 2013, over 300,000 SumOfUs members came together and successfully pressured Asos to suspend all sales of angora fur after an undercover journalist exposed the torture of angora rabbits in Chinese factories.

Now we must move them again. Big companies like Asos must do better and it is our duty to hold them to account. GMB has found the issues its members have raised so worrying they are calling for Parliament's Business Select Committee to hold an urgent inquiry. No-one should have to fear losing their job because they can't meet impossible targets, plan to join a union, or need to use the bathroom.

Will you stand with Asos factory workers and call for better treatment?

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