By David Shepardson
WASHINGTON (Reuters) - Three Democratic U.S. senators on Tuesday questioned the decision by Volkswagen AG's U.S. unit to delay a union election for workers at its Tennessee assembly plant.
Earlier this month, the largest German automaker won its bid to put off a union election for 1,700 workers at the Chattanooga plant until its challenge to a smaller United Auto Workers bargaining unit at the factory is settled.
The National Labor Relations Board in a single-sentence, 2-1 decision on May 3 granted Volkswagen's motion to stay an election petition filed by some of its workers last month.
Senators Gary Peters and Debbie Stabenow of Michigan and Sherrod Brown of Ohio wrote to Scott Keogh, president of Volkswagen Group of America, on Tuesday, expressing "deep concern with delays" to the election.
"We urge you to immediately drop any efforts to oppose or postpone the election," the said.
UAW spokesman Brian Rothenberg said: "Chattanooga workers just want the right to vote and have the same workplace rights as every other VW worker in the world."
Volkswagen did not immediately comment Tuesday.
In December 2015, 160 skilled trade maintenance workers voted to unionize and affiliate with the UAW, the union said. VW declined to bargain with the union, saying the unit needed to include both skilled trade maintenance workers and production workers.
Volkswagen has stated it is neutral on workers joining a union but the senators said its "actions suggest otherwise."
VW began production at the plant in 2011 and builds the Passat car and the Atlas SUV. In January, VW said it was investing $800 million to build a new electric vehicle in Tennessee and add 1,000 jobs at the Chattanooga plant that will begin EV production in 2022.
The senators "have heard that facility supervisors in Chattanooga are engaging in direct anti-union conversations with workers in the workplace, including pulling workers off the production line to ask if they support the union," they said.
In February 2014, workers at the plant narrowly voted against union representation, which had been seen as organized labor's best chance to expand in the U.S. South.
UAW membership has plummeted 75 percent since 1979 and now stands at about 396,000. The UAW has failed for two decades to organize foreign automaker plants in the United States.
(Reporting by David Shepardson; Editing by Jeffrey Benkoe)