More than half the staff at the Derby Playhouse are to lose their jobs following an extended summer shutdown for refurbishment.
The theatre will be closed from July until December for refurbishment
The theatre is making 36 employees redundant from the its main staff and the Playhouse's catering subsidiary.
A consultation between staff and managers began in April after the shutdown was announced.
Actor Ben Roberts, a member of the Derby Playhouse Supporters' Group, said the theatre may have to close for good.
"I think it's got very serious now, I think the theatre is in danger of closing, perhaps not in the immediate future but that's the general feeling," said Mr Roberts.
But Karen Hebden, chief executive of the Derby Playhouse, said the theatre would re-open.
"We will be re-opening on 2 December having done some essential maintenance capital work and having done some staff restructuring.
"We're going to be closed for five months. A large number of catering staff are part-time or only work as required when the venue is open at night.
"You can't justify - when using public money - keeping people on when there's absolutely no work for them to do," she said.
Some staff could be re-employed when the theatre's refurbishment is completed, but fewer people overall would be needed, she added.
The refurbishment work includes a new stage and an improved air conditioning system.
Plans for a theatre refurbishment have brought bad news for staff who will face redundancy as work is carried out.
The Derby Playhouse is to get a new stage and better air conditioning but a number of people will lose their jobs by the time the work is completed.
The theatre's traditional summer break will be extended by three months meaning productions will finish in July and restart in December.
Funding for the work has come from the Arts Council and Derby City Council.
Managers at the Playhouse were unable to confirm how many people would be made redundant but a 30-day staff consultation period has begun.