(Bloomberg Law) -- The union that won a landmark vote at a Starbucks Corp. location in New York state last week is trying to overturn an unsuccessful vote at another store.

The labor group, Workers United, urged the National Labor Relations Board in a filing late Thursday to reject the results of the failed union vote, saying that Starbucks waged a “shock and awe” campaign to intimidate workers.

“The psychological harm on the employees cannot be overstated, since they had to contend with dozens of managers in a frenzy of anti-union propaganda,” the union wrote in the complaint.

When reached for comment, a Starbucks spokesman referred to a Dec. 9 statement in which the company said the results were preliminary “with no immediate changes to our partner relationship as the NLRB process continues.”

Mail-in ballots from the Buffalo-area store had gone 12-8 against unionization, but the union’s attorney said last week that some votes had gone uncounted.

The union is trying to expand its foothold among the thousands of corporate-run Starbucks restaurants in the U.S. after last week’s win. Workers United, an affiliate of the Service Employees International Union, petitioned in August for store-by-store union votes at three restaurants in the Buffalo region. One of those votes is still pending the outcome of voter-eligibility challenges, but the ballots that were counted there trended in favor of the union.

The labor board has the authority to invalidate election results in response to conduct that could have changed the outcome and prevented workers from making a free choice about whether to unionize. Challenges to election results are considered by regional labor board officials, whose rulings can then be appealed to board members in Washington.

If the labor board certifies the union as the winner in one or more of the elections, Starbucks will be legally required to collectively bargain with workers at any store where the union prevailed. However, employers in that situation have sometimes refused to negotiate until they first have the chance to challenge the agency in federal court.

To contact the reporter on this story: Ian Kullgren in Washington at ikullgren@bloombergindustry.com

To contact the editor responsible for this story: Martha Mueller Neff at mmuellerneff@bloomberglaw.com

©2021 Bloomberg L.P.