The A.F.L.-C.I.O. and three other pro-labor groups filed a complaint with the Federal Election Commission on Thursday, alleging that Wal-Mart engaged in unlawful federal election activity. The complaint states that Wal-Mart used mandatory meetings to warn store managers and department heads that a Democratic victory in November would hurt the company by helping workers unionize.

According to reports in the Washington Post and The New York Times, the pro-labor groups included Change to Win Federation, a group of seven unions including the Service Employees International Union and the United Food and Commercial Workers; American Rights at Work, a union-financed advocacy group; and WakeUpWalmart.com, a pro-union group financed by food and commercial workers.

The groups argued that while federal regulations make it legal for companies to engage in political advocacy with high-level managers, low-level managers such as department heads are often hourly employees. Wal-Mart had allegedly argued that the Employee Free Choice Act is undemocratic because it would deny many workers the option of casting a secret ballot on unionization.

Wal-Mart spokesman David Tovar told the Wall Street Journal that the company's policies are clear regarding political activity, and that if anyone representing the company told associates how to vote, they were "wrong and acting without approval. We welcome the FEC looking into this, because we are confident they will find what we have known all along, that we did nothing wrong," Tovar said.