PrintWeek understands that the facility's 400 employees were informed of the proposal this morning.

Group operations director Peter Andreou told PrintWeek: "We have had to restructure the business based on the outlook within the market.

"We are still faced with increasing manufacturing costs and must ensure that we continue to deliver service and quality to our customers.  Therefore, addressing our capacity and cost base will support this. "

Sources close to the company claimed that closure does not necessarily appear inevitable. The plant could remain open if the workforce agrees to radical changes to working practices, including a pay cut.

Andreou said the Colchester announcement encompassed all of the planned changes within Polestar at this time, despite industry speculation about the possibility of further restructuring elsewhere in the group.

Polestar's announcement continues a startling opening to 2012 for the web-offset sector. Just six days into the year BGP has already asked staff to take a pay cut of almost 20%, while Wyndeham announced plans to make 86 redundancies at Wyndeham Heron.

Unite has said that the move was "something of a shock" because Polestar has other more vulnerable plants.

National officer Steve Sibbald said: "When a venture capitalist comes in, something dramatic is always bound to happen within the first six months or so.

"It doesn't look like the European market is picking up, which Sun Capital would have thought would happen when they bought Polestar.

"Our first priority will be to sit down with the company and save as many jobs as we possible can."