A federal labor complaint has been filed against Sen. Bernie Sanders' campaign just days after the Vermont independent had reached an agreement with his campaign's unionized staffers.

The complaint posted Monday on the National Labor Relations Board's website and noted by Bloomberg Law alleges several potential violations, including concerted activities (retaliation, discharge, discipline) discharge, illegal interrogation, repudiation and modification of contract.

A full text of the labor complaint has not been released yet, and it was filed by an anonymous individual from Iowa. The NLRB allows individuals who are not on the campaign staff to file a labor law violations complaint.

The charge comes as Sanders announced he has reached a labor agreement with his campaign staffers.

“I was insistent that everybody on our staff make at least $15 an hour, and in fact they're making $17 an hour," he said Tuesday on CNN. "The offer that we made to the union several months ago would have accomplished that. And I'm happy to tell you, by the way, that offer was just accepted."