By Sebastian Herrera

Federal labor officials are expected to begin counting the votes Thursday or Friday in a closely watched union election by Amazon.com Inc. workers in Bessemer, Ala., who are seeking to become the first company employees in the U.S. to gain union representation.

Since the voting concluded on March 29, the National Labor Relations Board has been processing ballots to ensure they are valid and allow both parties an opportunity to contest the eligibility of each one. The number of ballots cast totaled 3,215, according to the Retail, Wholesale and Department Store Union, which would represent the Bessemer workers if they vote to unionize. The union said there were hundreds of ballots challenged over voter eligibility during the processing of ballots. The labor board hasn't yet provided a tally of votes.

The election has drawn national attention because a vote to unionize in Bessemer could fuel other unionization attempts throughout the company, which employs roughly 950,000 people in the U.S., most at its hundreds of warehouses.

Organizers have said that forming a union would allow workers to collectively bargain over issues including safety standards, training and compensation. Some employees have complained both publicly and to the company about their workload and how the company monitors them through internal tracking systems. About 6,000 people work at the Amazon facility in Bessemer.

Amazon has said its pay and benefits rank among the best available for comparable jobs--employees are paid at least $15 an hour, more than double the minimum wage in Alabama. The company says it provides a competitive compensation package, which includes retirement and healthcare benefits that many workers appreciate.

Amazon is the nation's second-largest employer after Walmart Inc. The tech giant added 500,000 workers globally last year as its business thrived while many others were hammered by the effects of the pandemic.

NLRB officials are set to count the uncontested votes in favor and in opposition to the union in Bessemer during a live broadcast that reporters and others will be allowed to watch. The counting is expected to take less time than the first phase but could stretch for days. The labor board is expected to announce results at the end of the count.

The winning side will have to gain a majority of the total number of votes cast. If there isn't a clear majority given the number of contested votes, the matter could be decided in a federal hearing. Both Amazon and the union could also file actions to contest the outcome.

Amazon faces pressure from staff world-wide to change workplace policies related to employees' break time and pay and the rate at which they prepare packages. Employees are expected to fulfill hundreds of orders an hour while being monitored by Amazon and having two to three breaks during what can typically be 10-hour shifts.

Both the union and Amazon used a variety of tactics to reach workers, including mailing leaflets and sending texts. Amazon held meetings with employees to discourage them from voting to unionize and posted signs around the warehouse.

Celebrities and politicians from both major parties voiced support for the Bessemer workers, casting their effort as part of a wider battle for equality for working-class people and a check on Amazon's growth and power. President Biden in February called the election a "vitally important choice," and Republican Sen. Marco Rubio of Florida also publicly expressed support for workers, as did actors and athletes.

Union supporters and the company increasingly clashed as the final ballots were turned in. Dave Clark and Jay Carney, both senior executives at Amazon, have used Twitter, highlighting Amazon's pay and benefits, to counter claims by Sen. Bernie Sanders (I., Vt.), a frequent adversary, that the company mistreats its workers.

Write to Sebastian Herrera at Sebastian.Herrera@wsj.com

(END) Dow Jones Newswires

04-08-21 0544ET