Two trade unions are threatening to go on strike against Fisher and Paykel Healthcare.
The Engineering Printing and Manufacturing Union and the National Distribution Union are seeking a pay rise for workers of 5.7% and say the company's offer of 3% is too low.
The two unions represent a total of 900 workers in a factory in East Tamaki and have issued 14 days notice of strike action.
Company managers could not be reached for comment.
