Scott Brauer | Bloomberg | Getty Images Starbucks is asking the federal labor board to suspend all postal union elections nationwide, alleging board staff and the union that organizes its baristas for misconduct in the voting process. The Seattle-based coffee giant wrote in a letter to the National Labor Relations Board’s president and general counsel Monday that labor board officials acted improperly during an election in the Kansas City area and likely have acted similarly in other elections. Starbucks cited an NLRB practitioner who approached the company as a whistleblower. More than 220 Starbucks coffee shops in the U.S. have voted to unionize, according to an NLRB count Friday. An additional 34 elections have been ordered or are underway, and seven more outlets are waiting to schedule elections. Starbucks Workers United and the NLRB did not immediately respond to requests for comment from CNBC. In addition to requesting a halt to all scheduled mail-in elections, Starbucks is requesting that all future elections be held in person while the allegations can be investigated. According to Starbucks, NLRB officials allegedly coordinated with union agents to arrange for in-person voting at labor board offices during mail-in elections. The company also alleges that Workers United agents were given confidential, real-time information about specific vote counts so the union could target employees who had not yet voted. NLRB officials and Workers United then allegedly coordinated to cover up that activity, the company said. Starbucks letter details email correspondence that allegedly occurred between union representatives and labor council officials. The company said it was made aware of the content of the emails by the whistleblower. Starbucks said similar behavior has occurred in elections in Seattle and Buffalo, New York. “Until a thorough investigation is conducted, it is anyone’s guess how many elections in how many other districts have been similarly tainted,” the company said in the letter. Under interim CEO Howard Schultz, Starbucks has more aggressively opposed unionization efforts at its locations. So far, the number of unionized coffee shops is a small fraction of the nearly 9,000 Starbucks-owned coffee shops, but the coffee chain is working to limit union momentum. For example, the company announced a new round of wage increases in May for permanent workers, but said the changes would not apply to unionized locations, saying they would have to go through the bargaining process. Earlier this month, Workers United formally asked the company to extend wage increases to those locations. Starbucks also faces 284 unfair labor practice charges from the union, according to the NLRB. Allegations of the company’s misconduct include allegations that it illegally fired organizers, closed stores or harassed its employees to prevent baristas from unionizing. Starbucks has denied all allegations of union busting.