The US Senate Committee on Health, Education, Labor, and Pensions (HELP) invited Starbucks CEO and founder Howard Schultz to testify on March 9 regarding his company’s compliance with federal labor laws, according to a letter released by Senator and Committee Chairman Bernie Sanders (I-VT) on Wednesday. The invitation follows a wave of unionization amid unfair labor practice charges against the coffee industry giant. Currently, Starbucks faces around 500 charges from the National Labor Relations Board (NLRB) for unfair labor practices.

Sanders’ letter details that the HELP Committee has “jurisdiction over matters related to labor-management relations, including the National Labor Relations Act.” Such jurisdiction encompasses regulation of wages, employment hours, workplace safety and union relations. Therefore, the hearing would relate to Starbucks’ adherence to these acts and address the charges against it. Starbucks has demonstrated resistance against worker-led unionization efforts, including filing counter complaints against the unions in retaliation.

The invitation follows a previous letter from Sanders to Schultz dated October 4, 2022. The letter addresses reports that Starbucks engaged in “illegal union-busting tactics in an attempt to intimidate and dissuade” its employees from unionizing. Schultz has yet to respond to the allegations, according to a press release from Sanders.