Starbucks has questioned the legitimacy of elections held to unionize specific locations. A whistleblower told Starbucks “misconduct” occurred between the union and the National Labor Relations Board, the organization conducting the elections.

The allegations stem from a Kansas City location but Starbucks said it suspects misconduct is happening in other cities like Seattle, Washington and Buffalo, New York. Starbucks wrote a letter to the chairman and general counsel of the National Labor Relations Board on Monday. It cited an NLRB member coming forward with “misconduct” allegations between NLRB officials and union representatives.

According to the letter, NLRB officials allegedly worked with union representatives to arrange for in-person voting at the labor board’s offices during mail-in ballot elections. Starbucks wrote that Workers United workers were given confidential, real-time information about specific vote counts so the union could target employees who hadn’t voted yet. Starbucks wrote NLRB officials and Workers United then allegedly coordinated to cover up this activity.

As a result of these allegations, Starbucks has asked the board to suspend all mail-in voting in current elections. The coffee chain also requested future elections be held in-person only. Several locations across the country are taking part in these union elections. More than 220 Starbucks stores have already voted to unionize. The company has opposed employees’ unionization efforts.

A Buffalo-area store voted in December 2021 to become the first unionized Starbucks in the U.S. In May 2022, the National Labor Relations Board accused Starbucks of 29 charges of unfair labor practices related to the Buffalo effort to unionize, including “interfering with, restraining and coercing employees” that sought to unionize.

Starbucks is still searching for its next CEO, which interim chief Howard Schultz said will be an outsider. Former CEO Kevin Johnson retired in April, forcing longtime former CEO Schultz to step in for the transition.