Even as the nation’s main union for retail workers acknowledged that it lost a unionization vote on Friday at a Target store in Valley Stream, N.Y., it demanded a new election and accused the company of illegally intimidating workers.

The National Labor Relations Board announced on Saturday morning that 137 workers had voted against joining the union, the United Food and Commercial Workers, while 85 workers had voted for it. The unionization drive sought to make the store on Long Island the first of Target’s 1,750 stores in the United States to be unionized.

In a statement, the president of U.F.C.W. Local 1500, Bruce W. Both, said that the workers at the Valley Stream store had endured a “campaign of threats, intimidation and illegal acts by Target management.” As a result, he called on the National Labor Relations Board to direct a new election and order Target to cease its “illegal activity.”

Responding to the union’s allegations, Molly Snyder, a Target spokeswoman, denied that the company had engaged in any intimidation or illegal practices. “Target believes we have followed all laws as outlined by the National Labor Relations Board,” she said.