That is the view of Unite the Union Regional Officer Darren Rushworth after administrators were appointed at YM Group's well-known printing firm Pindar this morning.
Mr Rushworth said: "YM Group has behaved disgracefully it repeatedly promised workers would be paid and even encouraged them to undertake overtime, in recent days."
Specialist corporate restructuring company FRP Advisory has been appointed at YM Group's Pindar (Scarborough) Ltd in Eastfield, YM Chantry Ltd in Wakefield and York Mailing Ltd in York.
All operations at the sites have ceased and all of the company's staff have been sent home and made redundant.
Unite said workers at the sites were given payslips but no pay and that the administrators have confirmed 600 staff will not be paid.
Phil Pierce and Philip Watkins, partners at FRP, were appointed as joint administrators after a "period of challenging trading that had been exacerbated by the impact of the pandemic and rising prices".
Without the prospect of an investor or a sale, the three companies have ceased to operate and the majority of its 512 staff have been made redundant with a small number retained to assist administrators.
An accelerated marketing process in recent weeks failed to secure a buyer, the administrators said.
Phil Pierce, partner at FRP Advisory, said: "This has been an incredibly challenging period for the printing sector and York Mailing, YM Chantry and Pindar are no longer able to continue trading.
"Regrettably, the insolvency has led to redundancies at what we know will be an extremely difficult time. We will work with staff to access redundancy support."
YM Group filed Notices of Intention to appoint administrators at the High Court on Friday last week for its subsidiaries, including Pindar in Eastfield.
Nobody was available for comment when The Scarborough News contacted YM Group earlier today.
Mr Rushworth added: "Unite is providing every assistance to the workforce who are devastated by the way in which they have been treated.
"Unite will be providing legal support for its members across the three YM Group sites to make a protective award for the company’s failure to inform and consult them before they lost their jobs. This will eventually provide some financial compensation for the affected workers."
In its most recent accounts for the financial year to May 31 2020, Pindar had sales of £55.3m and made an operating profit of £613,000 while employing 274 staff.
Post-tax profit fell to £155,000 from £1.3m in 2019, which was due to the coronavirus pandemic, the company said.