Rep. George Miller, ranking Democrat on the House Education and the Workforce Committee, sent a letter to Tennessee Gov. Bill Haslam on Wednesday demanding "all communications" between state government officials, Volkswagen and any "third parties" regarding any proposed state financial incentives relating to the German automaker's Chattanooga plant. Miller wants to know whether state officials "conditioned ... state aid to Volkswagen on the outcome of efforts to establish a union and/or works council."

Tennessee media outlets have reported that internal documents show Haslam offered $300 million to Volkswagen as an enticement to expand production at the plant to include a new SUV line. The administration indicated that should the plant become unionized, the aid would no longer be available.

Miller argued in the letter that placing such conditions on aid "may undermine employees' federally-guaranteed freedom to choose whether or not to be represented by a union." The California congressman is a staunch supporter of Big Labor. The letter was also signed by Rep. John Tierney, D-Mass.

It would be a hard case to make that the incentives would have undermined those labor rights, though, since VW tacitly backed the United Auto Workers' effort to unionize the plant anyway. Workers nevertheless rejected UAW, 712-626, in a vote concluded Feb. 14. The existence of Haslam's aid package was not publicly known until after the vote, so it could not have influenced the workers' decision either.

UAW has filed a complaint with the National Labor Relations Board, calling on it to void the election and order a new one. A hearing before the NLRB is set for April 21.