A group of unions representing 5.3 million US workers in various industries has asked the Federal Trade Commission to investigate Amazon.com Inc’s growing economic power.

The group, which includes the International Brotherhood of Teamsters, the Communications Workers of America, the United Food and Commercial Workers and the Service Employees international Union, filed a petition on Feb 27 calling on the agency to investigate Amazon for a variety of potentially anticompetitive practices, including its "impact on wages”.

"Amazon is rapidly accumulating market power and dominating our economy, while it resists inquiries into the anti-competitive practices that have made its dominance possible,” Teamsters general president James Hoffa said in the release.

Amazon and chief executive officer Jeff Bezos, the world’s wealthiest person, have become symbols of inequality and a focus of the US presidential campaign. Senator Bernie Sanders, a longtime Amazon critic, pressured the company to raise its lowest wages to US$15 an hour. Amazon in October 2018 announced it would do so.

"No other US-based company has created more jobs than Amazon in the last decade,” the company said in an email. "In the US alone, Amazon has created over 500,000 jobs for people with all types of experience, education and skill levels.”

 - Bloomberg