Three workers at Volkswagen Chattanooga's plant have filed a federal lawsuit against their employer.
They say the company illegally worked with the United Auto Workers to sway workers to vote for unionization.
The lawsuit alleges that Volkswagen illegally provided "things of value" to the union. They say VW and the union made an agreement that would benefit both parties.
Among many of the claims, the plaintiffs say Volkswagen allowed UAW to use plant property to persuade workers and they held meetings during company time.
In exchange, the trio says the union told VW its workers would not go on strike. They also say UAW offered Volkswagen competitive advantages.
Workers rejected the union during a three-day vote last month.