United Grain locked out longshoremen on Feb. 27 after saying Todd Walker, a member of the union bargaining team, was responsible for damaging company equipment in December.

In its filing with the National Labor Relation Board, the local said the company can't punish all the workers for the alleged act of one person.

"This constituted loss of employment based on anti-union animus, and a sweeping unilateral change of terms and conditions of employment." the local said in the complaint.

Late last year, United Grain was among three Northwest terminal owners that declared an impasse in negotiations with the ILWU and imposed a contract that included new, management-friendly workplace rules.

United Grain said the sabotage occurred Dec. 22, just days before the impasse was declared. In a lawsuit filed against Walker, the company states he shoved a 2-foot-long metal pipe into a conveyor and poured sand into a gear box.

Vancouver police are investigating. Walker has not been charged with any crimes.

Union spokeswoman Jennifer Sargent said Walker is not available for interviews about the accusations or the lawsuit against him.

United Grain was "disappointed but not surprised" by the unfair labor practices filing and will cooperate with the NLRB investigation, said Pat McCormick, a spokesman for terminal owners.

"Case law has recognized, for decades, an employer's right to lock out employees in response to incidents of sabotage like those that have occurred at United Grain Corp.," he said in a statement. "Therefore, the actions taken to ensure the safety of United Grain employees and the security of our facilities were both legal and prudent."

United Grain, part of the Japanese conglomerate Mitsui & Co., said nonunion replacement workers will operate the Vancouver export terminal for an indefinite period. Longshoremen have conducted round-the-clock protests since the lockout started.

The union has sought to restart contract talks, but United Grain and the other terminal owners who declared an impasse — Columbia Grain and Louis Dreyfus Commodities — have not accepted.

"It's shameful that Mitsui-United Grain, a Japanese corporation that's profiting from the United States' infrastructure, natural resources and labor, has chosen to violate our federal law instead of negotiating a fair labor agreement with its American workforce," ILWU President Robert McEllrath said in a statement Tuesday.

McCormick criticized the union for consistently emphasizing the Japanese ties of the company. He said United Grain has been operated by Oregon and Washington residents for more than four decades,

"The union's constant reference to the parent company is a blatant attempt to try to confuse the public about the dispute and the parties involved," he said.