A Fonterra subsidiary has announced it's axing 30 jobs from a Hamilton canning plant.

Canpac has made the decision to take the metal decorator and press setter jobs overseas.

E Tu Union spokeswoman Fiona McQueen says there will be limited job opportunities for the highly skilled metal decorators around the country.

She says it has been a tough day for the workers.

"They're feeling really sad, they've tried really hard to improve the productivity of the plant and they haven't been successful."

She said more will be known about the workers' options after talks with Canpac next week.