The union representing soon-to-be laid-off paper mill workers in Quebec City will go to court to try to keep the White Birch Paper plant open.

White Birch is closing its Quebec City mill on Dec. 9, leaving 600 people out of work.

Daniel Larouche with the Communications, Energy and Paperworkers Union said he believes the closure is a lockout in disguise, as the workers were in the middle of contract negotiations.

The union plans to ask the Quebec Superior Court to halt the shutdown.

It will argue White Birch cannot act unilaterally, since it is currently under bankruptcy protection.

White Birch said the closure is temporary, but officials have not said when the mill will reopen. The company said it is assessing the mill's viability.