U.A.W. Seeks a New Election at Mercedes-Benz Plants in Alabama

A week after losing a hard-fought election at two Mercedes-Benz factories in Alabama, the United Automobile Workers asked federal officials on Friday to order a new vote, saying the German carmaker violated labor laws to suppress support for the union.

Mercedes-Benz conducted a “relentless anti-union campaign” marked by “wanton lawlessness,” the U.A.W. said in a complaint to the National Labor Relations Board. Among other things, the union said, Mercedes fired four employees who supported the union, prevented pro-union employees from campaigning and forced employees to watch anti-union videos.

Workers at the Mercedes factories outside Tuscaloosa, which manufacture sport utility vehicles and battery packs, voted 56 percent to 44 percent against joining the union. But the labor board can order a new election if, after a hearing, a regional director determines that improper conduct by an employer affected the vote, a spokeswoman for the board said.

Mercedes denied that it had used improper methods to defeat the union drive. A majority of workers “indicated they are not interested in being represented by the U.A.W.,” the company said in a statement on Friday.

“Throughout the election, we worked with the N.L.R.B. to adhere to its guidelines, and we will continue to do so,” Mercedes said.

The Alabama result interrupted a string of victories by the U.A.W. in the South, including persuading a large majority of the workers at a Volkswagen factory in Chattanooga, Tenn., to vote to join the union and securing substantial pay raises in a new contract with Daimler Truck in North Carolina.

Organizing workers in Southern states, which have long been hostile to unions, is a high priority for the U.A.W. The region is attracting a large share of the billions of dollars that companies are investing in electric-car and battery factories.

By the same token, Southern elected leaders like Alabama’s governor, Kay Ivey, a Republican, have worked to keep unions out, seeing them as a threat to their ability to attract more factories and jobs.