The National Distribution Union says Fletcher Building will close a wood products factory in Auckland with the loss of more than 80 jobs.
The Plyco Select plant in Penrose makes interior and entrance doors, and the union says it will close next month.
The union says the new government needs to act quickly to save job losses in the wood industry.
Fletcher Building has been closing plants and cutting production as the home-building market shrinks.
More than 300 Carter Holt Harvey workers are to lose their jobs when the company closes mills at Putaruru and Maunganui next month.
The union says Fletcher Building has already eliminated more than 700 jobs this year.