Simon Jones, Polestar Group HR director, said that if the deal went ahead, all 160 bindery staff at the Essex-based site would transfer under TUPE regulations.

Business Process Outsourcing (BPO) specialist Aktrion, which is a managed services provider to the print and automotive sectors, was unavailable for comment at the time of writing.

Aktrion's website lists two recent print outsourcing contracts, although neither would appear to refer to the deal with Polestar. The first is for a North West-based magazine printer which has outsourced the running of its bindery, finishing and palletizing areas, covering 40 staff across two shifts.

The second is for "a leading directory printer", where Aktrion is providing a team of bindery and polywrapping assistants to operate nightshifts.

Unite's national officer Steve Sibbald said Sun European Partners, Polestar's new owner, was trying to safeguard the terms and conditions of the staff, and added that Unite's members would be covered by TUPE legislation.

He said: "It looks like Polestar is selling off that side of the business in order to concentrate on their core areas.

"It's pure speculation on my behalf, but it seems a coincidence that this has happened following the purchase of Polestar by Sun European Partners."

Jones said the move was separate to the group's refinancing and change of ownership.