The Federal Trade Commission sued PepsiCo on Friday, alleging that it has engaged in illegal price discrimination by giving unfair price advantages to one large retailer at the expense of other vendors and consumers.

The Robinson-Patman Act was passed in 1936, but the federal government stopped enforcing it during the deregulation of the 1980s. The FTC resumed its enforcement in December when it sued Southern Glazer’s, the largest U.S. distributor of wine and spirits.

"Much of Walmart’s market dominance can be attributed to its use of this illegal and anti-competitive tactic," says Stacy Mitchell

The U.S. Federal Trade Commission sued PepsiCo on Friday for offering preferential pricing to a large retailer, whom a source familiar with the matter confirmed was Walmart .

The FTC sued PepsiCo on Jan. 17, alleging that it has engaged in illegal price discrimination by giving unfair price advantages to Walmart at the expense of other vendors and consumers.

The US Federal Trade Commission sued PepsiCo Inc. Friday under a rarely invoked 1930s law called the Robinson-Patman Act that bars price discrimination against retailers.

The FTC has filed a lawsuit against PepsiCo, accusing it of illegal price discrimination by giving preferential pricing to Walmart, disadvantaging other retailers and customers. PepsiCo disputes these allegations,

The commission alleges that the retailer, whose name was redacted in the statement from commissioners, received “unfair pricing advantages” that were not made available to others.

The Federal Trade Commission is suing PepsiCo for alleged price discrimination in the final days of the Biden administration.

According to the FTC’s complaint, Pepsi has been providing unfair pricing advantages to one of its largest customers—a major big box retailer—while raising prices for competing retailers and customers. Reuters reports that the retailer is none other than Walmart Inc. WMT , citing a source familiar with the discussions.

The practices fed high consumer prices by placing at a disadvantage other retailers, from large grocery chains to independent convenience stores, the FTC said