LONGVIEW, Washington (From The Daily News) -- KapStone's union mill workers overwhelmingly authorized an unfair labor practice strike this week, the union reported.

About 99 percent of voting union members approve of the strike authorization, officials of the Association of Western Pulp and Paper Workers said Wednesday night. Officials with Local 153 didn't say how many of the 800 members members voted Tuesday and Wednesday, just that it was a substantial majority.

The vote is an attempt to show that any strike would be over an unfair labor practice rather than purely economic concerns. KapStone could not legally hire permanent replacement workers if it was an unfair labor practices strike. Such a categorization would likely be contested by KapStone, because the company says it hasn't committed any unfair labor practices.

Last year, Local 153 filed a complaint with the National Labor Relations Board against KapStone, arguing that it hasn't furnished requested information to the union. A hearing for the complaint is scheduled in December.

KapStone Paper and Packaging Corp. and Association of Western Pulp and Paper Workers Local 153 have been bargaining for a new contract for more than a year.