The Meat Workers Union says its 1000 members at Affco plants in the North Island will go on strike for two days next week.
The union says members voted overwhelmingly for the strike action at the eight meat works after the company, owned by the Motueka-based Talley family, walked away from mediation last week.
Union national secretary Graham Cook said Affco was the first company to take advantage of an employment law change which allowed employers to walk away from mediation.
"Talley's is an outlier in the meat industry in the way it deals with employment relations and health and safety," he said.
Mr Cook said Affco had added new demands to reduce job security, threatened the union and others with legal action, and bullied their staff at work.
The strike is planned for Monday and Tuesday.
Comment is being sought from Affco.