A trade union representing meat industry employees says migrant workers have more job security than New Zealanders.
ANZCO Foods Limited, which processes and markets beef and lamb, has its foreign workers under a government agreement that guarantees them 12 months' employment.
Its Rangitikei plant was expected to end its night shift at the end of this week, but that has now been extended for at least another three weeks.
The Meat and Related Trade Union says foreign workers can be protected and paid $14.25 an hour, while New Zealanders may lose their jobs because they have no such rights.
Union secretary Graham Cook says he does not necessarily want the foreign workers sent home, but is simply asking for the same benefits for domestic employees.
He says about 75 New Zealand workers and 15 migrant workers are on the shift. Mr Cook fears it is the New Zealanders who will go first when it does close, which he claims is discrimination.
ANZCO and the Meat Industry Association declined to comment on the contract arrangement.