Manufacturing at the flagship Waterford Crystal plant in Kilbarry, Co Waterford is to cease, it has been confirmed today.
The move, which includes the closure of the visitors' centre, will result in 480 redundancies.
However, the receiver David Carson has stated that operations may resume in the future if a suitable buyer for the company is found.
"The receiver of Waterford Wedgwood plc, Mr David Carson of Deloitte, wrote today to staff at Waterford Crystal and Cash's Mail Order, informing them that manufacturing will cease with immediate effect at Kilbarry, Co Waterford," said an official statement from the receiver.
"As a consequence, approximately 480 employees have been made redundant. The visitors' centre in Waterford will also close.
"The decision to cease manufacturing does not necessarily preclude a resumption of operations in Waterford in the future.
"The receiver is continuing negotiations with interested parties with a view to a sale of the company's assets and those discussions are focused on agreeing the terms upon which a transaction could be completed."
An estimated 150 Waterford Crystal staff have been holding a sit-in at the plant today, insisting on a meeting with the receiver.
It is understood that minor scuffles have broken out between workers and security staff as tensions rise in the building.