The Employment Court has ruled that Open Country Dairy is not acting illegally in bringing in workers to replace factory staff during industrial action.
The Dairy Workers' Union had challenged the company's six-week lockout of workers at its Waharoa factory, as well as its use of staff from other factories while the dispute is on.
The court had last week ruled the lockout illegal, and in a decision released on Thursday said the company had the right to use the replacement workers.
Open Country Dairy says it has lifted the lockout but is still not allowing unionised staff back to work pending an investigation into what it calls environmental sabotage at the factory.
Dairy Workers' Union national secretary James Ritchie says its lawyers are now looking at the court's decision and deciding whether to appeal.
Mr Ritchie says the union will also challenge what it believes is a recent unfair dismissal of one of its delegates.
He says a new strike notice, which due to come into force on Saturday, remains in place.