Hundreds of workers have been seriously injured or narrowly escaped an accident at Amazon's UK warehouses over the last three years, new figures claim.
GMB union numbers show 240 reports of serious injury or near misses were sent to the Health and Safety Executive last year, and 622 over three years.
Amazon is currently running a TV advertising campaign highlighting contented staff.
It said critics were determined to present a "false picture".
The GMB obtained the figures via Freedom of Information requests.
For injuries to be included in the figures they need to be serious enough to stop a worker performing their normal duties for at least seven days, or be on a list including fractures, amputation, crushing, scalping or burning.
In one London warehouse a worker lost consciousness and appeared to stop breathing after injuring their head, the GMB said. In Manchester, one worker got caught in a gate and fractured their hand.
The data shows the number of reports to the HSE has increased every year, from 152 in the 2017 financial year to 240 in 2019. However the figures deal with a period during which the number of warehouses run by Amazon more than doubled from 10 in 2015 to 22 today.
Mick Rix, GMB national officer, said: "Amazon are spending millions on PR campaigns trying to persuade people its warehouses are great places to work. But the facts are there for all to see - things are getting worse.
"Hundreds of stricken Amazon workers are needing urgent medical attention. Conditions are hellish. We've tried over and over again to get Amazon to talk to us to try and improve safety for workers. But enough is enough - it's now time for a full parliamentary inquiry."
In December, GMB and the Trades Union Congress (TUC) were joined by members of the shadow cabinet for a demonstration outside Amazon's London offices. The unions and politicians said that Amazon should be paying millions more in taxes, claims denied by the online giant.
A spokesman for Amazon said: "Amazon is a safe place to work. Yet again, our critics seem determined to paint a false picture of what it's like to work for Amazon. They repeat the same sensationalised allegations time and time again.
"Our doors are open to the public, to politicians, and indeed to anyone who truly wants to see the modern, innovate and, most importantly, safe environment we provide to our people." Amazon has been running television commercials using warehouse staff to highlight a happy working environment.