Amazon has defeated activists hoping to establish the company's first unionised warehouse in the US.
Workers at the Bessemer, Alabama warehouse voted 1,798 to 738 against the effort, labour officials said.
That represented a majority of votes cast in the contest, which was seen as a key test for Amazon after global criticism of its treatment of workers during the pandemic.
The union said it would challenge the results.
It accused Amazon of interfering with the right of employees to vote in a "free and fair election", including by lying to staff about the implications of the vote in mandatory meetings and pushing the postal service to install a mailbox on company grounds in an effort to monitor the vote.
"Amazon has left no stone unturned in its efforts to gaslight its own employees," said Stuart Appelbaum, president of the Retail, Wholesale and Department Store Union (RWDSU), which organised the effort.
"We won't let Amazon's lies, deception and illegal activities go unchallenged, which is why we are formally filing charges against all of the egregious and blatantly illegal actions taken by Amazon during the union vote."
Amazon said on Friday that it was "not true" that it had intimidated staff.
It said the firm worked hard to listen to concerns and improve, casting the outcome as a choice by staff, rather than a company victory.
"We're not perfect, but we're proud of our team and what we offer, and will keep working to get better every day," it said.
What was the fight about?
RWDSU leaders had hoped that the pandemic, which sent Amazon's business soaring while exposing its workers to new health risks, had created an opportunity for the union to make inroads and set a new standard for Amazon workers across the country.
If successful, the union drive would have meant that Amazon, the second largest employer in the US, would have had to negotiate a contract with union officials on issues such as work rules and pay.
Organisers tied the fight at the warehouse - where the majority of the nearly 6,000 workers are black - to broader issues of civil rights and racial justice and cited complaints, such as intrusive monitoring and abrupt, impersonal treatment by management.
Amazon contended that the union did not represent the views of most of its staff.
It said it offered competitive salaries and benefits and told workers that the union would collect hundreds of dollars in dues without being able to deliver changes.
Rebecca Givan, professor of labour studies at Rutgers University, said she was not surprised by Amazon's win, given the outsize power employers have to fight union efforts under current US law.
"Employers have a huge advantage in these situations," she said. "They have almost unlimited money and almost unlimited access to the workers to bombard them with messages of anxiety and uncertainty and we see the result of that here."
Change will come?
Workers at Amazon's warehouse in Bessemer had one message after the outcome of the union drive was revealed - and it didn't matter which side they were on.
Both said they expected the vote - the first one Amazon has faced since 2014 - to make a difference.
At a press conference organised by Amazon, anti-union staff said the company had committed to reviewing concerns with workers at the facility over the next 100 days, like the need to give managers more training.
They said they hoped to work with colleagues who voted to unionise on the issues raised by the debate.
"We can get those same goals and things accomplished without a union," said Will Stokes, adding that he felt the complaints in articles about the campaign had distorted life at the facility. "We're not against unions - we just feel like at this facility in Bessemer, we don't need a union."
Meanwhile pro-union workers said they were not discouraged and planned to continue to push for improvements.
"Things will not stay the same after this point," said Emmit Ashford. "We will keep our heads held up, we will keep fighting ... It's not over. It's only a matter of time before things change."
The election in Bessemer, a town of 27,000 people outside of Birmingham, was closely watched.
Union membership has steadily dwindled in the US in recent decades, but the pandemic also re-ignited concerns about income inequality and worker safety, with Amazon drawing much of the public scrutiny.
Last month, US President Joe Biden called the vote a "vitally important choice". Celebrities and national Democratic politicians travelled to the state to support the union campaign, which even drew some Republican backing.
Christy Hoffman, general secretary of UNI Global Union, a global federation of unions, said Amazon's conduct during the campaign showed that US labour law was "broken".
But she said the movement had already inspired workers elsewhere.
"While this vote was happening, there were strikes in Germany and Italy, and a massive new effort to reach Amazon workers was launched in the UK. It will continue to give hope to workers demanding a voice at work and a job with dignity," she said.
"The impact of Bessemer has already rippled out far beyond the warehouse walls and cannot be understated."
A big win for Amazon
Amazon execs will be heaving a sigh of relief tonight.
The company has been desperate to avoid its workforce unionising, believing industrial action could threaten their business model of sending packages quickly and reliably.
It employed experts in their field at great expense to sculpt an anti-union narrative. Their attack line was that unions equalled uncertainty, would cost workers money in dues, and wouldn't necessarily fight for their needs.
The demographics of the workers in Bessemer led some to think the union had a chance.
Alabama isn't a place known as a hotbed of union action. However the workforce is around 85% black and majority female and the union thought that might help their cause.
Politicians too, from Democrat Bernie Sanders to Republican Marco Rubio backed the union. Joe Biden also supported the push.
The RWDSU will now appeal the vote, saying that Amazon used illegal tactics to win the vote.
For now though, this is a moment to savour for Amazon.