President Joe Biden met with a group of labor organizers Thursday at the White House, including a former Amazon.com Inc. worker who led a Staten Island union-organizing drive.

Christian Smalls, the Amazon organizer, took part in a roundtable session hosted by Vice President Kamala Harris and Labor Secretary Marty Walsh. The session included young organizers and workers at a range of companies.

“Today I met with grassroots worker organizers to thank them for their leadership in organizing unions,” Biden tweeted Thursday, adding that Smalls and other union officials “are inspiring a movement of workers across the country to fight for the pay and benefits they deserve.”

Biden has regularly chided Amazon, and expressed support for the union push at the company last month. “By the way, Amazon, here we come,” he said at the time.

Smalls’s fledging Amazon Labor Union won an election in April to represent Amazon workers at a warehouse in New York’s Staten Island. Amazon has contested the result. The union this week lost an election at a second, smaller Amazon facility across the street.

Smalls on Thursday also testified at a hearing presided over by Senator Bernie Sanders, who has proposed barring U.S. companies that violate labor laws from winning federal contracts. The Vermont independent said Amazon has “done everything possible — legal and illegal — to defeat union organizing efforts.”

The Sanders proposal faces long odds. Identifying federal contracts linked to Amazon would be difficult, owing to limited disclosure and the company’s choice of selling its cloud products through dozens of resellers and systems integrators.

A Bloomberg Government analysis of non-classified contracts and announcements of classified work reveals direct and indirect government sales could exceed $3 billion annually as recent contracts take effect over the next two years. In the government’s current fiscal year alone, Amazon bagged $367 million worth of contracts spread across 93 vendors and 33 agencies, according to publicly disclosed data.

The Bloomberg Government analysis excludes Amazon’s multi-billion-dollar, classified contracts with the Pentagon and the intelligence community, the value of which are not recorded in publicly released contracting data. The calculation also excludes the office supplies and other items that government agencies buy from Amazon’s web store.

Amazon didn’t respond to a request for comment on the hearing or Sanders’ allegations.

The company is grappling with an increasing number of unfair labor practice complaints from workers around the country. Employees have lodged 51 complaints so far this year, many of which came from Amazon locations in Staten Island and Bessemer, Alabama, where organizing efforts have been underway.

In his testimony, Smalls said federal contractors can break labor laws and get away with it and that the process workers can use to hold companies accountable is no longer working.

“It’s not a left or a right thing, it’s not a Democrat or Republican thing. It’s a worker thing,” Smalls said.