Workers at German car giant Volkswagen's Chattanooga factory in Tennessee have voted to join the United Auto Workers trade union, in a major boost for the largest car union in the US outside its powerbase in Detroit. 

Well over half of eligible workers cast ballots, making the result binding. 

And of those who voted, 2,628 were in favor and 985 against, a 73% level of support for unionizing. 

Workers celebrated the result, cheering and waving their "Union Yes" campaign posters as the outcome was announced late on Friday. 

Even President Joe Biden commented on the results, having voiced support for the move in the run-up. 

"Together, these union wins have helped raise wages and demonstrate once again that the middle-class built America and that unions are still building and expanding the middle class for all workers," he said in a statement.

Union presence rare in US South and West

Friday's result will make Chattanooga the first auto plant in the South to unionize via an election since the 1940s, and the first foreign-owned plant in the South to do so. 

VW held a neutral posture in the vote, with unionization the norm at its facilities around the world, including in its native Germany. It used to have a UAW presence at its defunct plant in Pennsylvania far to the north, until that closed in 1988. So the vote appears more likely to lead to a deal rather than deadlock. 

UAW President Shawn Fain has been trying to extend the influence of the US' main car workers' union beyond the historic automotive capital of Detroit where it's focused. 

Fain and his team have committed to spending more than $40 million (€37.5 million) through 2026 in a bid to unionize plants owned by a variety of carmakers in other parts of the US, including Tesla. 

"I'm exhilarated that we actually accomplished what set out to accomplish," VW employee Lisa Elliott said after the results were announced. "Tell Mercedes they're next." 

That was a reference to a Mercedes plant in Alabama, which will be the next facility to hold a UAW election during the week of May 13. 

Wage deals with 'Big Three,' Biden on Detroit picket 

It was the third attempt to affiliate with UAW at the factory, with votes in 2014 and 2019 narrowly failing. Other votes at other factories, like a Nissan facility in Mississippi in 2017, also failed. 

But this year's vote had coincided with a boost in public support for unions in the US, which can be fairly skeptical of organized labor by international standards.

Republican governors in six southern states, including Tennessee, have spoken out against the move to unionize car plants in recent months.

The UAW last year securing big pay settlements with the "Big Three" US carmakers — General Motors, Ford and Stellantis (more commonly still called Chrysler) — after President Biden walked a Detroit picket line also brought the group into public focus. 

The union has indicated it is also eyeing a Hyundai factory in Alabama and a Toyota facility in Missouri where it says that more than 30% of staff have already signed cards indicating they want a vote on joining. 

msh/nm (AFP, AP, Reuters)