Amazon was accused of "dehumanizing" its employees to deliver products to customers.
Workers at the online shopping giant's distribution centers face disciplinary action as they lose a punitive race against the clock to track items ordered by online shoppers.
Staff paints a picture of a stressful environment dominated by the beeps of handheld devices – nicknamed the "gun" – and giving instructions on which items to collect.
Bosses are said to push personnel so far beyond the border that they practically burn, while regular layoffs to keep the workers on their toes were described by an HR manager as "Darwinism."
According to a discovery last year, the company's best employees are referred to as "Amabots" – because they are "one with the system", they are almost cyborgs.
In Tilbury, Essex, shocking claims were made in November about the online retailer's newest warehouse, which the company calls the fulfillment center.
The packaging plant is the largest in Europe, has the size of 11 football fields and will ship 1.2 million items this year.
In Tilbury, Essex, shocking claims were made in November about the online retailer's newest warehouse, which the company calls the fulfillment center
The investigation by a covert Sunday Mirror reporter who spent five weeks there indicated that workers suffer mentally and physically as they try to satisfy demand.
He said that some of his colleagues were so tired of having worked 55 weeks that they would sleep "on their feet".
"Those who could not keep up with the punitive targets stood in front of the bag – and some who were under stress had to be accompanied by rescue teams," he added.
It was not until the following month that Amazon drivers were asked to submit up to 200 parcels a day, less than the minimum wage, and to urinate in bottles, as there was no time for a break
Law firm Leigh Day, which has filed a lawsuit against taxi giant Uber, has seven drivers claiming that the agencies used by Amazon are abusing them.
While Amazon does not directly engage drivers, drivers hired through agencies work through an Amazon app and follow company delivery routes.
Drivers who receive up to 200 parcels a day say that congestion, weather and speed limits make it nearly impossible to deliver all packages on time.
An Amazon spokesperson said, "Amazon offers a safe and positive workplace. The safety and well-being of our permanent and temporary staff is our top priority. "