SEATTLE – By the end of Monday, thousands of yellow envelopes mailed to a squat brick building in Birmingham, Alabama will portray the fate of one of the most closely watched union elections in recent history that could change the shape of the movement and one of the largest America’s employer.

The envelopes contain the voting papers of workers in an Amazon warehouse near Birmingham. Nearly 6,000 employees at the building, one of Amazon’s largest, can decide after years of fierce opposition from the company whether to form the first union at an Amazon company in the United States.

The organizers have argued in a month-long campaign that the intensive monitoring of workers by Amazon violates their dignity and that the pay does not correspond to the constant pressure workers feel to produce. The union estimates that around 85 percent of the labor force in the camp is black and has linked the organization to the fight for racial justice.

Amazon countered that its $ 15 minimum wage is twice the state minimum wage, and that it offers health insurance and other benefits that are hard to find in low-wage jobs.

“Even the fact that the vote is taking place is a referendum on what is called the future of work,” said Beth Gutelius, a researcher who studies the warehouse industry.

Regardless of the outcome of the vote – which may not have been known for days – the union movement has already managed to anger the world’s largest e-commerce company and spotlight complaints about its work practices. The vote comes at a delicate time for the company, which is increasingly being scrutinized in Washington and around the world for its market power and influence, which has increased during the pandemic as consumers flocked online to avoid business. President Biden has signaled his support for the workers, as have many progressive leaders.

If the retail, wholesale and department store union succeeds, it would be a great victory for the labor movement, which has been declining in membership for decades. A victory would also enable them to gain a foothold in the country’s second largest private employer. The company currently employs 950,000 people in the United States after hiring more than 400,000 people last year alone.

If the union is losing by a large margin, Amazon has turned the tide for a union movement that apparently has many winds in its back. A loss could force workforce organizers to rethink their overall strategy and give Amazon confidence that its approach is working.

The union action has drawn national attention in part because of the nation’s focus on key workers during the pandemic and on racial inequalities highlighted by the Black Lives Matter movement.

“Of course we want to win,” said Vermont Senator Bernie Sanders on Friday when he visited Alabama. “But I think an important point has already been proven. And that means that even in the deep south the workers are ready to stand up, organize and fight for justice. “

In Bessemer, Ala., A union-friendly radio commercial paid for by Black Lives Matter was broadcasting on a local R&B station while every intersection around the warehouse was crowded with signs. “Bama has your back! Vote union! The big building was wrapped in sky-blue banners that read “VOTE”. On Friday, an Amazon employee drove a golf cart across the parking lot to fend off the news media.

A union victory “could change the labor movement as we shift in the definition of who workers and union members are,” said Sara Nelson, president of the flight attendants’ association, who visited Bessemer this month and felt “overwhelming”. local support for the union.

But if the workers vote against the union, Ms. Nelson said, the result would be “pretty devastating”. Ms. Nelson said, “People would have a hard time believing it because of what they were going through on the ground.”

Mr. Sander’s visit seemed to have hit a nerve with Amazon. After announcing the trip, Dave Clark, who runs Amazon’s business and the global consumer business, attacked Mr. Sanders in a series of messages on Twitter, as well as the company’s official social media account. “I often say we’re the Bernie Sanders’ employers, but that’s not entirely true because we actually offer a progressive job,” Mr Clark wrote in a tweet.

Amazon has said it doesn’t believe the union represents the majority of its workers. It refused to speculate on what would happen after the vote.

“While we don’t know how the vote will end, we believe we have opened the door to more organization across the country,” said Stuart Appelbaum, the union’s president, in a statement. “And we showed how far employers will go to destroy their workers in order to gain a union vote. This campaign is the best example of why we need labor law reform in this country.”

The union efforts came together quickly, especially for someone aiming at such a big goal. Workers at the Bessemer building reached out to the local branch of the retail workers’ union last summer. In October, the organizers showed up at the camp every day and tried to talk to the workers between shift changes.

By the end of December, more than 2,000 workers had signed cards saying they wanted an election. The Labor Authority found that this number showed enough interest to hold a vote.

Amazon wanted the vote to be in person as usual, but the National Labor Relations Board found the pandemic made it too risky and ordered a mail-in poll.

The ballot papers were mailed to workers in early February and must be signed and received by the Labor Department at their Birmingham office by the end of Monday.

The vote counting begins on Tuesday – a process that can take many days.

First, an employee of the employment office reads the names of the employees without opening an inner envelope with the actual voting slip. Union and Amazon representatives will be participating in a private video conference. As each name is read, the names of the employees are checked against a list of employees. If either side disputes whether this worker was eligible to vote, that ballot will be held. It is also expected that a representative from each side will be personally on site to observe the process.

After the two sides have had an opportunity to object to eligibility, the NLRB will begin counting the undisputed ballots. After every 100 votes, the labor authority counts these ballots again until all votes have been counted. This part is open to reporters on a video conference line.

If there are more controversial ballots than uncontested ballots, it will likely spark legal arguments from the union and Amazon about the eligibility of any controversial ballot. Each side has about a week to comment before the NLRB confirms the vote.

Either side can dispute whether the vote was conducted fairly. For example, the union could argue that the company took steps to improperly influence the vote by potentially fearful of retaliation for workers if they supported the organization.

If the union prevails, workers fear the company could shut down the warehouse. Amazon has pulled back from places that previously gave it a headache. In 2000 a customer service office was closed trying to join forces in union organizations. The closure is the result of restructuring. It stopped building an office tower when Seattle tried to tax the company and pulled out of plans to build a second headquarters in New York City after facing progressive opposition.

However, the company has allocated more than $ 360 million in leasing and equipment for the Bessemer warehouse, and shutting down the votes of a large black workforce could publicly backfire, said Marc Wulfraat, a logistics consultant who is closely following the company.

Regardless of the outcome, Mr Wulfraat said the election is a sign that Amazon has work to do. “For most companies that organize workers in some way,” he said, “it didn’t happen because they did a fantastic job of managing people.”

If the union loses, Amazon will lose at least one customer: Michael Render, the rapper for Killer Mike. When he appeared next to Mr. Sanders on Friday, he said, “If this vote doesn’t go through and these conditions don’t improve, I won’t be ordering from Amazon again.”

Sonam Vashi reported from Bessemer, Ala.