An email from GMG chief executive Andrew Miller, sent to all employees, confirmed that the company was looking into its print strategy in a bid to improve the company's efficiency.

Miller said that changes already in place, such as scrapping the G3 inserts and cutting pagination had already led to savings, but "we need to do more".

"We expect Monday to Friday print to carry on declining," he said. "We have discussed with Unite a number of proposals, including a reduction in the workforce.

"We are also looking at a wide range of potential longer-term options for our printing operations, one of which would be to move them to a third party."

Speculation has emerged that the company is in talks with rival publisher Trinity Mirror to move the Guardian to its Watford plant. Under the plan, the company would move its Berliner presses to Trinity's plant.

Trinity also has a plant in Oldham, while News International's Knowsley facility may also have room to contract print should GMG choose to move all of its titles. Trinity Mirror declined to comment.

If GMG were to move to contract print it would mark a major reversal for the business as its Stratford plant was only built in 2005, at a cost of £80m.

The Guardian has been one of the hardest hit national titles in recent years and in August its subsidiary Guardian News and Media reported an operating loss of £38.3m for the year, although GMG did report a small profit.