The publisher of The Herald in Glasgow has warned journalists that it is seeking to make new cost savings of up to £2m.
According to the NUJ, it is the fourth time in the past five years that Newsquest has sought to make severe cuts at The Herald, Sunday Herald and Evening Times.
NUJ Scotland organiser Paul Holleran said: "People are in a state of shock. We held a health and safety survey recently and the results were horrendous with really high stress levels."
In May, Newsquest announced it was cutting 40 jobs - including 20 in editorial - across its Glasgow titles as it integrated them into one 24-hour newsroom producing print, web and mobile news stories.
According to the NUJ, some staff believe the new £1m editorial system has made working conditions worse rather than more streamlined.
Holleran said: "The system is completely flawed and is crashing two or three times a day with people losing pages every hour."
Glasgow Herald editor Charles McGhee is currently working his notice after announcing his decision to resign in July.
The NUJ believes that new cuts of £1m are being sought in editorial with a further £1m from elsewhere in the company - and that this could mean 50 job cuts.
In a memo to staff, Herald management said: "The Herald and Times Group, in line with much of the UK newspaper industry, is in the throes of an unprecedented economic downturn.
"The impact of the credit crunch is accelerating and is impeding our ability to both maintain and grow new sustainable newspaper advertising revenues.
"Since the beginning of the year, the publishing business has seen rapidly decreasing revenues.
"This, coupled with increasing utility costs, has resulted in the publishing business experiencing unacceptable pressure on profits with no sign of recovery in the coming months. The company must take action now to secure its future.
"Each department head has been asked to review costs including staffing levels, taking into consideration the impact of new technology and taking into account deliverable strategic cost efficiencies through changes to existing working practices."
An NUJ chapel meeting is due to take place at the papers tomorrow.