Former workers at an Amazon warehouse complain of timed toilet breaks, punishments for talking and zero-hour contracts in an exclusive Channel 4 News investigation.

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Channel 4 News spoke to a dozen ex-employees at Amazon's massive packing warehouse in Rugeley, east Midlands, who were angry at how the internet sales giant treated them.

They said Amazon made them work long hours with minimal breaks, and laid off temporary staff to avoid giving them the same benefits and rights as permanent workers.

The staff claimed their movements were monitored by GPS trackers, and say they were only given 30 minutes for lunch in a ten-hour shift - 20 minutes of which were spent walking to and from the canteen.

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Workers were searched for stolen goods at airport-style security checkpoints before going into the canteen.

The employer allegedly issued penalty points to workers - for talking to colleagues, taking sick leave, or even spending too long in the bathroom – on a "three strikes and you're out" basis.

'No job security'

The staff claim that the firm uses so-called zero hours contracts extensively, which means those staff have no job security and are forced to make themselves available for work with no guarantee they will be offered a shift on a particular day.

One former agency manager also alleges that Amazon tried to avoid paying out hundreds of pounds in accrued holiday pay to agency staff by instructing agency representatives not to inform employees that it was owed to them.

Andy Kingsley, who says he used to work for the recruitment agency Randstad inside the Rugeley warehouse, told Channel 4 News: "I think it was very underhand and devious to tell people not to claim money that they'd earned.

"It was left down to the agency reps to instruct the associates as to what their next step was."

Ranstad told Channel 4 News it had launched an investigation into the allegations and would take appropriate action if required.

Bussing in workers from elsewhere

Former employees say working conditions are so bad that local people in Rugeley devastated by the closure of its coal mine are now refusing to work at Amazon, which is bussing in agency workers from elsewhere.

Amazon said it employs over 4,500 permanent employees in the UK and has invested over a £1 billion pounds here.

It added: "In Rugeley, we have 401 permanent associates, 345 of whom started on temporary assignments. We expect to hire an additional 250 permanent associates in Rugeley in the next year.

"All our agencies are contractually obliged to pay holiday pay and that is accounted for in the amounts we pay to agencies.

"We continue to listen to feedback from associates, as well as customers, in order to learn, innovate and improve and are proud of being part of the Rugeley community."

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