A spokesperson said closure was one of the options being considered.
Sonae Industria Group said it began the process as a result of long delays to the reconstruction of the factory due to "political and planning difficulties".
"It is with great sadness and regret that after 12 years of operating in Knowsley, consultation will commence on the future of this factory," said Sonae Industria (UK) Ltd managing director Nigel Graham.
For more on this story see next week’s issue of TTJ.
