Job losses are forecast in Christchurch as a prominent plastic card maker heads across the Tasman.

Around 50 workers at ABCorp have been told of the company's intention to close the plant by the end of March and move to New South Wales.

E Tu spokesperson Joe Gallagher said while a final decision hasn't been made yet, it's not looking good.

He said it's come out of the blue, and a short three-week consultation period leads them to believe the company's made up its mind already.

The company makes products like bank cards, ID cards and loyalty cards.