"Over the past 18 months, Starbucks has waged the most aggressive and illegal union busting campaign in the modern history of our country," said Senator Bernie Sanders, Chair of the Senate Health, Education, Labor, and Pensions Committee, adding that Schultz led the company's anti-union campaign.

Starbucks has denied allegations that it illegally fired pro-union baristas or spied on workers as hundreds of stores organized unions starting in late 2021. It also says it did not violate federal labor law by offering some new benefits only to non-unionized stores, as the National Labor Relations Board has alleged.

"These are allegations and Starbucks has not broken the law," Schultz told Sanders during the hearing.

Schultz, who left his third stint as CEO on March 20, said he did not have any direct role in firing workers who supported the union or closing unionized stores. He remains on the company's board.

His return to Starbucks as its interim leader in April 2022 was "95% focused on the operations of the business" and his involvement in the company's union strategy has been "de minimis," Schultz said.

(Reporting by Hilary Russ in New York and David Shepardson in Washington; Editing by Nick Zieminski)

By David Shepardson and Hilary Russ