Longshoremen locked out of their jobs at a Pacific Northwest grain terminal have filed an unfair labor practice charge, alleging the company's action is an "extreme" and illegal response to an act of sabotage allegedly done by one union worker.

United Grain Corp. imposed the lockout last week after it determined that a union leader damaged company equipment in December.

The unfair labor practice charge was filed by Local 4 of the International Longshore and Warehouse Union. It was filed with the National Labor Relations Board's regional office in Seattle.

Members of Local 4 have been picketing since Feb. 27 at United Grain's gate at the Port of Vancouver, Wash.