A complaint issued today by the National Labor Relations Board alleges that six employees of Jimmy John’s, an Minneapolis area fast food restaurant, were unlawfully disciplined, threatened, and ultimately terminated for engaging in union and other concerted protected activities.

According to the complaint, the six employees were fired on March 22 and 23, 2011, because of their support for the Union, and also because of their concerted protest about Jimmy John’s sick leave policy. Another four employees were given final written warnings for engaging in the same conduct.

The complaint alleges several additional violations by the employer, including disparaging and threatening pro-union employees on Facebook, removing union postings from stores, interrogating employees about their union activities, and threatening mass firings for union organizing.

In an informal settlement agreement reached earlier this year between Jimmy John’s and the Industrial Workers of the World, which had attempted to organize store employees, store managers agreed not to discipline or threaten employees because of their union activities, and not to withhold raises because of an ongoing union campaign, among other things. All of these activities are illegal under the National Labor Relations Act, which guarantees private sector employees the right to organize.

Absent a settlement, the case will be heard before an Administrative Law Judge on January 17, 2012.