The administrators of Woolworths have announced 450 job losses on the day of a half-price sales event.
Administrators at Deloitte said the redundancies will be in head office and support roles in London and Castleton, Rochdale.
There have been no redundancies at the retailer's stores, where additional staff have been hired to cope with the expected demand today.
Neville Kahn, joint administrator and reorganisation services partner at Deloitte, said: "Unfortunately, it has been necessary to make some 450 employees redundant out of a total workforce of over 25,000.
"Our expectation remains that stores will remain open beyond Christmas and that all staff in the stores will be paid in full."
Mr Kahn added: "We have today launched Woolworths' biggest ever sale, which is complementary to and will not adversely impact upon our efforts to sell the business."
Highlights of the sale will include up to 50 per cent off toys, 30 per cent off Christmas trees and decorations, 50 per cent off all greeting cards, 20 per cent off personal gifts and reductions on all entertainment products.
Job Centre staff will be at both sites to provide support and advice to employees who have been made redundant, and the Insolvency Service's Redundancy Payments Service has put together a special team to quickly approve claims for employee entitlements, the administrators said.