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.
"It is obvious because they have locked them out from 3am on Friday to 3am on Tuesday," said Mr Eastlake.
"It's just a cynical move to get out of paying statutory pay on Good Friday and Easter Monday."
He said that despite assistance in Work and Income emergency benefits and financial donations from other union members, there was "undoubted hardship" as some workers had been locked out for more than five weeks.
"I daresay there's a lot of hardship but there's not much we can do about it because they don't seem in any hurry to talk to us,' said Mr Eastlake. "But of course people's attitudes harden and the people who are locked out know what their employers think of them."
Affco operations manager Rowan Ogg said the company was making good on a promise it delivered to workers in a letter more than two weeks ago that it would "not be comfortable" paying for statutory holidays to people who engaged in strike action.
Mr Ogg said Affco had provided a date for negotiation, which the Herald understands is April 12.
He said it would take "some substantial movement" from the union for the stalled collective contracts negotiations to progress but locked-out workers had a choice: "They can sign an individual employment agreement and return to work."
Mr Eastlake said the union wanted to renegotiate a collective employment contract for its members but Affco had "put in a number of clauses and conditions we aren't comfortable with" and wanted to individualise contracts.