A coalition of unions representing 5.3 million workers is pushing the Federal Trade Commission (FTC) to investigate Amazon for anti-competitive business practices.

The 28-page petition, filed Thursday, asks the FTC to look into Amazon's "immense and growing influence" in the economy. The group includes the International Brotherhood of Teamsters, the Communications Workers of America, the United Food and Commercial Workers International Union and the Service Employees International Union.

The unions laid out a number of issues they think the FTC should examine, including whether Amazon "depresses wages" in markets where it's a major employer, whether the company favors products on its site that pay for Amazon services and whether Amazon abuses its dominance in cloud computing, by serving as both a "retailer of software and as platform."

"Given the speed at which Amazon continues to amass market power and the company's persistent disregard for the inquiries of the legislative branch, we submit that a more forceful inquiry is needed," the petition states. "It is imperative that the FTC call on Amazon to answer the charge that it is using exclusionary conduct to the detriment of workers, consumers, merchants, and competition itself."

An Amazon spokesperson told CNBC that the company represents less than 4% of U.S. retail and highlighted the company's record of job creation. Those are stats the company routinely points to when facing criticism over its market power.

"The fact is that no other U.S.-based company has created more jobs than Amazon in the last decade," the spokesperson said. "In the U.S. alone, Amazon has created over 500,000 jobs for people with all types of experience, education and skill levels."

An FTC spokesperson confirmed they received the petition but declined to comment further.

The petition comes as Amazon faces the growing specter of antitrust action. Amazon is already being probed by FTC officials over its business practices in retail and cloud computing, according to reports from several outlets. The Department of Justice and the House Judiciary Committee have both opened broad antitrust reviews of Big Tech.