By William Boston in Berlin and Ben Foldy in Detroit 

The United Auto Workers is wrapping up a vote Friday at Volkswagen AG's auto factory in Tennessee that will determine whether the 84-year-old union will be successful in achieving a long sought-after goal: organizing its first foreign-owned car plant in the U.S. South.

Around 1,700 of the factory's 3,800 employees are eligible to vote in the election. Workers began casting ballots on Wednesday on whether they want the UAW to represent them in collective bargaining with the German auto giant, and results are expected late Friday night.

If the UAW prevails in unionizing the plant, it will be a historic win for a labor organization that has spent decades trying to build influence outside of Detroit and represent more factory workers across the car-manufacturing sector. The union's membership, which hit a peak of 1.5 million workers in 1979, has fallen to about 400,000 last year as Detroit's big three car companies have closed U.S. plants and moved more factory work to Mexico and other countries, where labor is cheaper. While the foreign-car companies build millions of vehicles each year in the U.S., none of their assembly plants are unionized. Most reside in right-to-work Southern states, where antiunion sentiment runs strong.

"It's a big deal for the union as far as their growth and, they think, their future," said Art Schwartz, president of consulting firm Labor and Economics Associates.

A victory in Tennessee also would strengthen the UAW's hand ahead of contract talks this fall with Ford Motor Co., General Motors Co. and Fiat Chrysler Automobiles NV for new four-year labor agreements at their U.S. factories. In the past, the Detroit companies have used wage comparisons at nonunion plants, which typically pay workers less, to argue against pay increases for their own factory workers, said Mr. Schwartz, a former labor negotiator at GM.

The UAW tried once before to organize workers at VW's only U.S. auto plant, holding a unionization vote in 2014 that was narrowly defeated, 712 to 626. Since then, the union has established a union hall, UAW Local 42, near the factory in Chattanooga, Tenn., and won a vote to organize a smaller group of skilled tradespeople at the factory -- a victory Volkswagen has challenged.

Volkswagen, one of the world's largest car companies by sales, has union representation at its other factories world-wide except for China, where there is state control of labor markets. Half of the company's supervisory board is composed of labor leaders from Germany's powerful IG Metall trade union. The Tennessee factory, which opened in 2012 as the U.S. car market rebounded following the recession, builds the Passat sedans and a new large SUV model, called the Atlas.

During the 2014 vote, Volkswagen worked with the UAW to coordinate public statements and worker communications at the plant about the election. State politicians and antiunion groups, however, campaigned against the UAW, an effort the union blamed for the loss.

But this time around, the car company has been more active in trying to convince workers a nonunionized factory is a better option. Volkswagen has established a website dedicated to the election that emphasizes improvements made for workers at the plant, as well as links to antiunion editorials and news articles about a U.S. Justice Department investigation into corruption allegations at the UAW. The UAW has said the misconduct was limited to a few individuals and it has cooperated with the government probe.

State and local politicians also have weighed in on this latest Tennessee vote, trying to dissuade workers from joining a union.

In an April visit to VW's plant, Tennessee Gov. Bill Lee used remarks to employees to advocate for a union-free workplace, attracting cheers and jeers from the crowd, according to comments recorded during the meeting and confirmed by his office. A "no" vote would be "in the best interest of the workers of Volkswagen and really for the economics of our state," Mr. Lee told reporters during an event in Tennessee last month.

The IG Metall trade union has supported the UAW's efforts, criticizing Volkswagen management for trying to sway the vote in the weeks leading up to the election.

"Antiunion leaflets have been passed around in the plant; supervisors are asking [employees] to give management a chance to solve the problems without the union," a spokeswoman for IG Metall said in an email.

A Volkswagen spokesman said the company will remain neutral throughout the process and respects employees' right to decide. It has highlighted recent moves to address worker concerns, including raising wages and reducing overtime, and emphasized it is investing more than $800 million into the factory to make it a hub for building electric vehicles.

The UAW, which represents about 155,000 hourly workers at U.S. factories operated by Ford, GM and Fiat Chrysler, has been trying to convince Chattanooga's workers they deserve the same voice in how their plant is run that is afforded to other VW employees around the world.

A union contract would provide consistency around plant policies on overtime and promotions, said Steve Cochran, president of UAW Local 42 and a worker at the Chattanooga plant.

"People want to have a structure and they want the rules to be set; that way, they know what to expect when they come into work," Mr. Cochran said.

As Toyota Motor Corp., Daimler AG and other foreign-based car companies have shifted factory work to the U.S., they have elected to build large assembly plants in right-to-work states in the South, far from the union strongholds in Michigan.

The move has helped bring thousands of new jobs to states that have long struggled to attract manufacturers, but the wages have historically been lower than those at Detroit's unionized factories.

Factory wages at the Detroit car companies top out at close to $30 an hour for longer-tenured workers. At Volkswagen, the top wage is $23.50 an hour for assembly-line employees.

The UAW has made numerous attempts to unionize workers at the foreign-owned car factories, including holding organizing drives at Toyota and Nissan Motor Co. But the efforts have yet to yield results, and local politicians often warn workers a vote to unionize a plant could hurt future job security.

The union has had more success organizing smaller auto-parts suppliers and employees working in other industries, such as higher education and gambling.

Write to William Boston at william.boston@wsj.com and Ben Foldy at ben.foldy@wsj.com

(END) Dow Jones Newswires

June 14, 2019 11:56 ET (15:56 GMT)