Jobs are expected to go at print firm Bezier after it went into administration.
The company, which has its headquarters on Balne Lane, Wakefield, and sites in Leeds and Poole, Dorset, has already made 254 staff redundant.
A further 148 staff are being kept on at the company, which has appointed administrators from Deloitte, but further job losses are expected.
The move follows reports that Bezier had lost a string of contracts, including a deal with Boots thought to be worth £10m.
An employee who spoke anonymously claimed staff were not paid for last week’s work.
He said: “It’s horrible at the moment. People don’t know what to do because if they leave they won’t get redundancy or be able to claim benefits.”
A Deloitte spokesman said all staff who had been retained were paid for hours already worked and would be paid in full during the period of administration.
He said: “Unfortunately, due to the nature of the business being insolvent, there aren’t sufficient funds to pay the accrued wages of staff made redundant.
“However, those staff are entitled to make a claim to the government’s Redundancy Payment Service for payments such as redundancy, lieu of notice, holiday and backdated pay.”
Earlier this week, Bezier chief executive James Buckley said: “It has been an incredibly tough trading climate for print manufacturing businesses as new forms of marketing replace more traditional forms of print media.
“In making this decision we had to take a view of what was best for the whole company going forward and deeply regret the staff redundancies.
“This decision has not been made lightly and comes despite a series of stringent organisational changes designed to reduce costs. Unfortunately the current situation has become unsustainable.
“We are extremely grateful to all our colleagues for their dedication and will do our utmost to support them through this transition.”