By Sebastian Herrera

Federal labor authorities rejected Amazon.com Inc.'s request to delay a union election at one of its warehouses in Alabama, clearing the way for thousands of workers to begin casting their votes this month.

The National Labor Relations Board denied Amazon's request Friday, saying the company didn't raise any substantial issues warranting review of the election. The online shopping giant asked the board in late January to postpone the union vote scheduled to begin Monday at its facility in Bessemer, Ala. Amazon also asked authorities to reconsider allowing mail-in voting due to the pandemic. The workers have until late March to return their ballots in an election that could reshape Amazon's relationship with its hourly employees.

An Amazon spokeswoman said the company was disappointed by the board's decision. Amazon "proposed a safe on-site election process validated by Covid-19 experts that would have empowered our associates to vote on their way to, during and from their already scheduled shifts," she said.

"It's long past time that Amazon start respecting its own employees," said Stuart Appelbaum, president of the Retail, Wholesale and Department Store Union, or RWDSU, which would represent the employees if they vote to unionize. Amazon must allow its workers "to cast their votes without intimidation and interference," he said.

The union, which has become a frequent Amazon antagonist in recent years, has sought to garner support by rallying employees through family members and union members who work in other industries. Workers who want to unionize said doing so would let them bargain collectively over safety standards, training, breaks, pay and other workplace matters.

Amazon employees have never formed or belonged to a union in the U.S., and labor experts say unionizing in Bessemer could lead to similar efforts at other Amazon facilities. Organizers there launched their campaign in the fall and collected thousands of worker signatures in support of the union. They have set up a presence outside near the 855,000-square-foot warehouse almost daily, talking to workers at a traffic light and handing them fliers.

Amazon, which has long opposed unions, launched a website to encourage employees to vote against unionizing and has posted signs around the warehouse with that message. Employees say the company also has been holding frequent meetings inside the facility to counter the union's effort. Amazon has said that it provides workers with ample benefits and doesn't believe the union represents most employees' views.

Labor experts say that while the current effort has had more success than other attempts to organize at Amazon, the organizers' goals would be difficult to achieve. Amazon has easier access to its workers than does the union, and a vote in favor of unionizing could lead to years of bargaining over a contract.

The union campaign in Alabama is one of several tests Amazon has faced recently. Federal regulators have continued to probe the retailer's business practices as part of an investigation into the market powers of large technology companies. In addition, Connecticut is investigating how Amazon sells and distributes digital books, and investigators in California are looking into how the company treats sellers in its online marketplace.

Amazon also is preparing for a change in leadership, with Chief Executive Jeff Bezos saying Tuesday that he is stepping down to become executive chairman. Andy Jassy, the head of the company's cloud-computing business, is set to succeed Mr. Bezos in the third quarter.

Despite the challenges, Amazon's business has never performed better. The company this week reported record fourth-quarter sales of $125.5 billion and net income of $7.2 billion, capping off a 2020 in which the pandemic fueled its financial performance.

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

(END) Dow Jones Newswires

02-05-21 1621ET