Walmart alleged in a complaint filed with the National Labor Relations Board that protesters affiliated with the United Food and Commercial Workers stormed one of its stores in Dearborn, Mich., in November, chased an employee into a ladies' room and "coercively interrogated" her. At least one of the protesters involved was a man.

As a result of the charges, the NLRB's regional director for Michigan filed a cease and desist order against UFCW on March 31. The union has until April 14 to respond to the charges.

The complaint involves an incident Nov. 23. A UFCW Local 876 organizer reportedly entered a Dearborn store without permission with 50 to 80 other protesters. The group remained in the store and blocking off its electronics section for 10 to 20 minutes before leaving.

Walmart further alleges about seven women and one man from the group "entered the women’s rest room inside the Charging Party’s Dearborn store, and coercively interrogated an employee regarding her wages, hours and working conditions."

At press time, UFCW had not responded to a request for comment. A source inside the union did not dispute Walmart's version of the protesters' actions but denied that UFCW had directed them to do that.

UPDATE: A spokesperson for the UFCW-affiliated Making Change at Walmart stated: "These actions were not committed or directed by any UFCW or OUR Walmart representatives. OUR Walmart never instructed anyone to block any part of any Walmart store, interfere with Walmart's operations or associates' work or commit actions that violated the NLRA or any other laws. We look forward to our day in court."

The charges are the latest in a long-running battle between the nonunion retail giant and the union, which represents workers for many of Walmart's rivals like Giant and CVS. Last year, the NLRB announced it was pursuing possible sanctions against the retailer for allegedly retaliating against workers who joined in 2012 protests organized by the union.

Those protests involved activist groups called OUR Walmart and Making Change at Walmart. Both are nonprofit groups backed by UFCW and created for the purpose of being able to protest Walmart without running afoul of federal labor law. The NLRB cease and desist order requires UFCW to post "appropriate notices" regarding the prohibited activities on its own website and the two groups.

Hat tip: WFB's Bill McMorris