Walmart faces National Labor Relations Board sanctions for allegedly retaliating against workers who joined union protests last year during the Thanksgiving holiday against the nonunion retail giant.

The agency confirmed the sanctions after union-backed activist groups OUR Walmart and Making Change At Walmart announced them earlier Monday in a conference call.

The sanctions involve alleged illegal threats, firings, and other disciplinary actions against 117 workers.

"The Office of the General Counsel has authorized complaints on alleged violations of the National Labor Relations Act. If the parties cannot reach settlements in these cases, complaints will issue," NLRB spokesman Gregory King said.

“We were informed by the board today,” said Dan Schladerman, director of Making Change at Walmart. “The settlement would have to include putting people back to work with back pay.”

Walmart spokesman Kory Lundberg said the action was “just a procedural step” and Walmart will defend itself because “our actions were legal.”

The fact is, we provide good jobs and unparalleled opportunities for our associates. This is our busiest time of the year and we're focused on serving our customers and helping them have a great holiday season.

It's important to note that there has not been one decision in the last 5 years by the NLRB or by a court finding that Walmart violated the National Labor Relations Act. That is because we take our obligations under the Act very seriously and we train our managers accordingly.

Lundberg declined further comment.

Union-backed activist groups have been targeting Walmart for years. They organized a series of post-Thanksgiving “Black Friday” protests against the retailer last year, hoping to hurt it during one of the busiest shopping days of the year. They are planning another round next week.

The union groups were also involved in publicizing reports Monday that a Canton, Ohio, Walmart had created a food bank for employees, citing this as proof Walmart pays its employees too little.

A Walmart worker told the Cleveland Plain Dealer that the bank was a longstanding employee project that helped co-workers who had recently experienced hard times, like a family member being in legal trouble.

The groups work closely with Big Labor. Also on the conference call with OUR Walmart on Monday were AFL-CIO President Richard Trumka and United Food and Commercial Workers President Joseph Hansen. Both groups support the anti-Walmart effort.

“It speaks forcefully to undercut [Walmart’s] argument and their credibility about having an anti-retaliation policy,” Trumka said of the NLRB action. “This shows they have been retaliating. An independent agency has now said what they did violates the law on a nationwide basis."

NLRB General Counsel Richard Griffin, whose recess appointment to the board was opposed by Republicans as illegal, initiated the action. Prior to joining the NLRB, Griffin was a top lawyer with the AFL-CIO-affiliated International Union of Operating Engineers. Trumka and other Big Labor groups pushed the White House to appoint him as counsel.

The anti-Walmart groups' actions have thus far attracted only a very small number of Walmart's 1.3 million employees. The retailer claimed only 50 workers joined last year's Thanksgiving protests. Few protesters at other events have turned out to be Walmart associates. Most appear to have been activists bused in for the events.

Press releases from the activist groups include the unusual disclaimer: "UFCW and OUR Walmart have the purpose of helping Walmart employees as individuals or groups in their dealings with Walmart over labor rights and standards and their efforts to have Walmart publically [sic] commit to adhering to labor rights and standards. UFCW and OUR Walmart have no intent to have Walmart recognize or bargain with UFCW or OUR Walmart as the representative of Walmart employees."

The disclaimer serves to protect OUR Walmart from charges that it is engaged in illegal union organizing activities. Under labor law, groups cannot protest a company for more than 30 days without filing notice that they seek to organize its workers. After that, the protests must end. The disclaimer allows OUR Walmart to stage continual protests despite the fact that it is an arm of UFCW, which has a well-know and longstanding interest in organizing Walmart employees.

The pro-business group Worker Center Watch attacked the NLRB in a statement: "The NLRB should focus on prosecuting OUR Walmart for dodging labor law and disclosure requirements rather than propping up the UFCW's attacks. While the Obama administration couldn't deliver on card check and other union goodies, its newly stacked NLRB is handing the unions an early Christmas present to the detriment of American workers."