(Bloomberg) -- Starbucks Corp. violated federal law by refusing to fairly negotiate with workers at dozens of newly unionized cafes across the country, US labor board prosecutors alleged.

The general counsel of the National Labor Relations Board determined that the coffee chain violated labor law by refusing to participate in collective bargaining sessions if some workers were present via videoconference, agency spokesperson Kayla Blado said Monday.

The company can agree to amend its practices or face complaints by regional NLRB directors around the country, Blado said.

Starbucks declined to comment. The company previously said that it is Starbucks Workers United that is refusing to negotiate fairly by insisting that workers be allowed to participate in talks via Zoom.

The Seattle-based company also said all claims of anti-union activity are “categorically false,” and that NLRB officials are pursuing cases in an effort to change labor law by overturning existing precedents.

Participation in negotiations via videoconference has been a flashpoint across the country.

The union has said that workers have reasons, such as Covid-19 restrictions, for wanting to participate virtually, and that management representatives have walked out of bargaining sessions within minutes, rather than allowing remote participation.

Complaints issued by regional labor officials are considered by agency judges whose rulings can be appealed to NLRB members in Washington, and from there to a federal appeals court.

A formal complaint by the NLRB “would mean a lot, because Starbucks has walked out of so many bargaining sessions,” said Los Angeles barista Tyler Keeling, a member of the union’s national bargaining committee. “We had our first bargaining date in October and Starbucks walked out after three minutes.” 

NLRB regional directors have issued 80 complaints against Starbucks over its response to activities by Starbucks Workers United, which has organized around 300 of the company’s 9,000 corporate-owned US stores since late 2021.

The coffee chain’s just-departed chief executive officer, Howard Schultz, is slated to testify Wednesday before a US Senate committee about the company’s handling of the campaign.

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