Senator Bernie Sanders said Friday he wants Amazon founder Jeff Bezos to testify at a hearing on what the progressive lawmaker called a "union-busting" campaign at one of the e-commerce giant's facilities.

Sanders said he asked the tech baron to appear at a Wednesday committee hearing to discuss the union election being held at Amazon's warehouse in Bessemer, Alabama.

The former presidential candidate said Amazon "is currently engaged in an aggressive union-busting campaign against Amazon workers in Bessemer, Alabama to stop them from collectively bargaining for better wages, benefits, and working conditions."

Among the witnesses called will be Jennifer Bates, an Amazon worker at the fulfillment center.

Sanders said in a tweet that he "invited" Bezos "to explain to the American people why he thinks it's appropriate for him to spend a whole lot of money denying economic dignity to workers at Amazon, while he has become $78 billion richer during the pandemic."

US lawmakers, left to right, Jamaal Bowman, Nikema Williams, Terri Sewell, Cori Bush, and Andy Levin visit the Amazon Fulfillment Center after meeting on March 5 with workers and organizers involved in a contested unionization effort
US lawmakers, left to right, Jamaal Bowman, Nikema Williams, Terri Sewell, Cori Bush, and Andy Levin visit the Amazon Fulfillment Center after meeting on March 5 with workers and organizers involved in a contested unionization effort GETTY IMAGES NORTH AMERICA / Megan Varner

Amazon did not immediately respond to an inquiry on whether Bezos, who is the world's richest person, would appear at the hearing.

The hearing comes amid a contentious union drive which would, if successful, result in the first US collective bargaining unit at Amazon, which employs some 800,000 people in the United States.

Celebrities and political leaders have expressed support for the union effort and President Joe Biden said last month the election should go on with "no intimidation, no coercion, no threats, no anti-union propaganda."

Sanders said he was calling the hearing on the growing crisis of wealth inequality and stated that "during the pandemic, 664 billionaires in America have increased their wealth by $1.3 trillion."

Amazon has said the majority of its workers did not want to join a union and has defended its policies which include a $15 minimum hourly wage. But it has created a website and distributed flyers with the slogan "DoItWithoutDues," which encourage workers to vote against the labor initiative.