The Meatworkers Union has disclosed a letter from AFFCO management threatening a lockout over Easter of all workers who take part in strike action at the company's freezing works.
The threat would deprive striking workers of pay for two statutory holidays.
About 1000 AFFCO workers are locked out at six plants throughout New Zealand, but 700 are still working.
Those 700 are planning another of a series of two-day strikes on Thursday and Friday in support of locked out co-workers.
But the letter from AFFCO says if they do that or take other strike action between now and a week after Easter, they will not get paid for Easter Friday and Monday.
The union says this is bullying behaviour intended to demoralise the workforce.
But management at AFFCO say they do not feel comfortable about paying statutory holiday money to striking workers when non-striking workers get the same deal.
The letter says the company needs to know who will be available so it can manage the flow of livestock and meet customer orders.