(Bloomberg) -- Organizers of union drives at Amazon.com Inc. and Starbucks Corp. will visit the White House on Thursday, a show of support by the Biden administration for the movement to unionize workforces at the companies. 

Vice President Kamala Harris and Labor Secretary Marty Walsh will host Christian Smalls of the Amazon Labor Union as well as officials from unions organizing workers at Starbucks, outdoor retailer REI and the video game publishing company Paizo Inc. among others, according to a White House official. 

Harris and Walsh will talk to union officials about their efforts to organize their workplaces and how they can inspire other workers to join or form their own unions, according to the official. 

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In the past couple of years, workers at several of those companies have been successfully signing up coworkers and petitioning the government to hold elections on forming or joining unions that can bargain with management for better working conditions.

Smalls’s upstart Amazon Labor Union last month won a historic victory in an election 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. 

Senator Bernie Sanders, a longtime critic of Amazon, has proposed banning federal contracts with companies that have allegedly violated U.S. labor laws and is holding a hearing Thursday on the matter. 

Earlier: Biden Warns Amazon ‘Here We Come’ After New York Union Vote 

Amazon workers lodged 51 unfair labor-practice complaints against the company in the first four months of this year, more than quadruple the number filed in the same period a year earlier. Most of the complaints came from Staten Island and Bessemer, Alabama, where a retail union is also seeking to organize an Amazon warehouse, alleging the company illegally retaliated against or monitored activists. There have also been complaints from workers in Florida, Nevada and Amazon’s home state of Washington.

Federal labor board prosecutors have found merit in some of the claims; Amazon has denied wrongdoing.

President Joe Biden has called himself the most pro-union president in U.S. history, but the White House has largely refrained from directly intervening in union drives. 

Nonetheless, Biden took aim at Amazon last month during a speech to the North America’s Building Trades Union. 

“By the way, Amazon, here we come,” the president said. “Watch. Watch.”

White House Press Secretary Jen Psaki later said Biden was not “sending a message that he or the U.S. government would be directly involved in any of these efforts or take any direct action.”

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