MoveOn.org has jumped into the fight for a unionized Wal-Mart workforce.

The liberal group has sent emails to its list nationwide, urging a mass-protest outside Wal-Mart stores on Black Friday. The organization is encouraging people to strike against management even if they aren’t Wal-Mart employees themselves.

“Instead of listening to and learning from its workers, Wal-Mart has sought to silence us and retaliate against those who dare to speak up,” MoveOn.org said in its email to supporters. “Warehouse workers who work for Wal-Mart contractors have also experienced retaliation for speaking out. Now, Wal-Mart workers have had enough.”

Black Friday is traditionally the busiest shopping day of the year.

“On Black Friday, and throughout the Holiday Season, we’re standing up for an end to the retaliation against workers who speak out for what’s right for our families, our communities, and our country,” the left-wing organization continued. “Will you show your support?”

Liberal union groups OUR Wal-Mart and Making Change at Wal-Mart, which are working to organize the planned strike, are aggressively trying to harness dues from Wal-Mart’s massive workforce.

But Wal-Mart is notorious for opposing organized labor’s efforts to unionize its workforce.

At every turn, since the days Sam Walton ran the company, Wal-Mart has mostly won its battles against those unions. That hasn’t stopped the nation’s big labor unions from continually trying to pry their way into the Arkansas-headquartered superstore chain, however.

In recent weeks, unions have stepped up their efforts to gain influence among Wal-Mart’s workforce, which is one of the largest in the country — totaling about 1.4 million people nationwide, by MoveOn.org’s estimates. Such a large workforce would potentially bring in billions in union dues for whichever labor group gets to the workers first.

The unions have tried various demonstrations, and are threatening these Black Friday strikes across the country to force Wal-Mart into caving on collective bargaining and other labor union demands.

But with a liberal National Labor Relations Board — one that will stay that way for at least the next four years because of President Barack Obama’s re-election — the unions appear emboldened. (RELATED: Top NLRB attorney charged with ethics breach in Wal-Mart stock case)

Even so, CNN reports that Wal-Mart has fought back against these recent union attempts to take over the company’s workforce. Wal-Mart filed a complaint with the NLRB, alleging that United Food and Commercial Workers (UFCW) union bosses were violating the law by organizing “flash mobs” and other activities that potentially violate the National Labor Relations Act.

“The UFCW has orchestrated numerous pickets, mass demonstrations, flash mobs and other confrontational activities both inside and outside Wal-Mart facilities in support of its bargaining and recognition demands,” Wal-Mart counsel Steven Wheeless wrote in the company’s NLRB complaint. “Now, with the busiest shopping season of the year just days away, the UFCW is openly orchestrating and promoting attempted mass disruptions of Wal-Mart’s customer shopping experience.”

An earlier version of this story connected the liberal financier George Soros with MoveOn.org. Soros was a major contributor to one of MoveOn’s political organizations more than six years ago, but does not appear connected to its current Wal-Mart protests.

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