Freezing works company Affco will not be paying striking workers holiday pay over Easter.
The company is locking out the workers from six of its eight North Island plants on Good Friday and Easter Monday.
The meat workers union says 1500 workers will be locked out, but Affco believes the number is well under 1300 because some workers have been working during the strikes.
Affco director of operations Rowan Ogg says workers were warned three weeks ago they would be locked out during Easter if they continued to strike.
He says the workers have elected to take their strike action despite the warning.
Meat Workers Union general secretary Dave Eastlake says Affco, which is part of the Talley group, is trying to get rid of union members.
He says the workers would not normally have worked on the public holidays, but would have been entitled to statutory holiday pay for Good Friday and Easter Monday.
Affco has agreed to attend mediation with the union on 12 April.