Maintenance workers at Silver Fern Farm's Takapau plant are going on strike, for what they is an unfair wage increase.
Nineteen staff members will go on strike from 3 January for three days, after more than a year of bargaining has turned sour.
Negotiations had seen their wage increase offer of 1 percent rise to 1.5 percent.
E tū delegate Brendon Illsley said the offer is "Just not good enough."
Mr Illsley said the workers work long hours to keep the plant running, from plumbing to fixing machines.
"We're not asking for much, but 1.5 percent is too little, we're not trying to be greedy," he said.
The government has confirmed the minimum wage will increase to $16.50 on the 1st of April.
E tū organiser Laurel Reid said the gap is now tightening between the minimum wage and what the workers are being paid.
"It impacts on their families, they need to be able to keep above the minimum wage, that's going up 4.8 percent. These guys are being offered 1.5 percent, which is in jeopardy now because they haven't accepted to this point and they want a fair increase for the second year," she said.
She said the skilled workers have a trade and should be paid accordingly.
"These guys are fully qualified fitters. People with trades are usually way above the minimum wage, the gap is closing on them and their skills aren't recognised as much as they should be," she said.
She said the workers are now falling behind on industry standards, and their calculations show they've fallen behind by about 10 percent of what other companies are paying trades people.
Ms Reid said workers will be picketing outside the plant on Wednesday and if changes aren't made there will be further strike action.