Amazon workers in Bessemer, Alabama, have voted in a historic poll to decide whether they want to be represented by the Retail, Wholesale and Department Store Union.
The results are not expected until next week – but if they say yes, it will become Amazon’s first US union.
Amazon argues its wages and benefits are industry-beating and has gone into battle to persuade workers to vote no.
Most agree the outcome could have major implications for US labour laws.
Peter Romer-Friedman, principal of law firm Gupta Wessler PLLC, said: “The key question in America at the moment is are we going to have fair treatment of workers in the businesses that will dominate our future?
“There will be ramifications for the real economy but also for tech firms.
In the US, Amazon has 800 facilities staffed by 950,000 full- and part-time workers – and it should be said many do not feel the need to join a union.
And for those who do, this is not primarily a wages issue – in fact, Amazon pays workers an average of $15 (£11) a hour, plus benefits.
But most agree conditions in its warehouses can be hard – the job is very demanding and lots of workers complain of back pain or other physical niggles as a result of working long hours, often standing in the same position.
Others talk about the mental-health toll of repeated tasks or feeling like they are a cog in a very big machine that does not always listen to their problems.
And there are a lot of things workers feel they do not have control of, such as shift patterns, time off, sick leave and being fired.
One of the most controversial features is time off task (TOT).
When a worker is clocked in, Amazon’s computer system calculates which hours of a shift are on or off task, based on whether or not an item is scanned.
And some say they feel dehumanised by technology watching their every move.
Amazon issued an extraordinary tweet last week, in response to US congressman Mark Pocan repeating an oft-heard complaint workers sometimes urinated in bottles because they did not feel they had time to visit the toilet.
“Paying workers $15 an hour doesn’t make you a ‘progressive workplace’ when you union-bust and make workers urinate in water bottles,” he wrote.
Amazon News replied: “You don’t really believe the peeing in bottles thing, do you?
Amazon’s tweet was shared thousands of times, with most people saying it reflected badly on the company.
The claim can be traced back to James Bloodworth, who worked undercover at a UK warehouse while researching his book on low-paid British workers.
And he responded to the Amazon News tweet by tweeting: “I was the person who found the pee in the bottle.
”trust me, it happened.”