“The employer’s flagrant disregard for the board’s typical mail-ballot procedure compromised the authority of the board and made a free and fair election impossible,” Henderson said in her decision. “By installing a postal mailbox at the main employee entrance, the employer essentially highjacked the process and gave a strong impression that it controlled the process. This dangerous and improper message to employees destroys trust in the board’s processes and in the credibility of the election results. "

For more reporting from The Associated Press, see below.

The board has not yet determined the date for the second election and it hasn’t determined whether it will be conducted in person or by mail.

About 53 percent of the nearly 6,000 workers cast ballots during the first election.

“Our employees have always had the choice of whether or not to join a union, and they overwhelmingly chose not to join the RWDSU earlier this year,” she said. “It’s disappointing that the NLRB has now decided that those votes shouldn’t count.”

Stuart Appelbaum, president of the RWDSU, saw the NLRB decision as a victory.