If the small group of Amazon workers in Delaware vote Wednesday to join a machinists' union—the first union shop in Amazon's vast warehouse network—the labor organization could spread to similar facilities across the country, a union representative told CNBC.
"A strategic plan would come together and we would start looking at other locations or within the location on how to go forward," said John Carr, a spokesman for the International Association of Machinists and Aerospace Workers, during a "Squawk on the Street" interview Wednesday.
The 30 Amazon mechanics voting Wednesday on whether to join the machinists' union represent a small fraction of the workers at their Middletown, Del., facility. Carr said hundreds more work in "the picking and the packing" of Amazon deliveries.
Carr would not say whether he had enough votes to officially organize the Amazon mechanics. As of December 2012, Amazon employed 88,400 full- and part-time employees.
"That remains to be seen," Carr told CNBC. "It's an uphill battle for the workers in the workplaces across this country and Amazon has made no bones about ... their anti-union stance and what they're willing to do to stave off unions in their workplaces."
The IAMAW needs a simple majority from the 30 workers to establish the union.
In response, Amazon spokeswoman Kelly Cheeseman said her company had an open-door policy and offered highly competitive wages, benefits and tuition reimbursements.
"We firmly believe this direct connection is the most effective way to understand and respond to the needs of our workforce and do not believe there is a need for third-party representation," Cheeseman said in a statement.
"Amazon's culture and business model are based on rapid innovation, flexibility and open lines of direct communication between managers and associates."
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The union vote adds to the many labor issues Amazon must contend with after its working conditions have come under growing scrutiny in the U.S. and abroad.
—By CNBC's Jeff Morganteen. Follow him on Twitter at @jmorganteen and get the latest stories from "Squawk on the Street."