CHATTANOOGA, Tenn. (AP) - Four workers at Volkswagen's plant in Chattanooga have filed complaints with the National Labor Relations Board saying the company is coercing employees into approving the United Auto Workers as their bargaining agent.

Volkswagen's top labor official, Bernd Osterloh says that Chattanooga would need to organize in order to compete for a new SUV that VW hopes to build in the U.S., requiring 800 new workers.

Matt Patterson leads the anti-union Center for Worker Freedom at the Americans for Tax Reform.

Patterson told WPLN-FM in Nashville that comment sounds like a threat to him.

UAW Regional Director Gary Casteel told the Chattanooga Times Free Press the cards signed by the workers clearly state the workers are supporting the UAW's effort to represent them.