Hundreds more Affco workers will be locked out over the Easter break, joining more than 1000 who are already on the picket line.
Union organisers say the move will save the company thousands in statutory holiday pay.
National Meat Workers Union spokesman Dave Eastlake said 480 workers at eight of Affco's North Island plants would be locked out on Good Friday and Easter Monday.
Their numbers will add to the 1000-plus workers locked out since the end of February.
Mr Eastlake said the move would save Talley's, the food processing giant which owns the Affco plants, hundreds of thousands of dollars in statutory holiday pay and the union was seeking legal advice.