One of Nottingham's best-known tourist attractions is facing closure within weeks, managers said.
The Tales of Robin Hood is the only attraction in Nottingham dedicated to the folk hero.
Ian Walker of Tales of Robin Hood said they were "in acute danger" of having to shut within a fortnight.
He said rent increases were causing problems, but a spokesman for the firm that sublets the property to him said it was willing to continue discussions.
He added: "This will be a great shame for the city of Nottingham as we are the only attraction that is dedicated to the world-famous legend".
Robin Hood legend
Mr Walker called on the city council to "come to Robin Hood's rescue" and help keep the attraction open.
A total of 40 staff, including 15 full-time employees, would lose their jobs if the centre closes.
Visitors to the attraction are told about the legend of Robin Hood through interactive displays.
Mr Walker said: "What is particularly frustrating is through BBC TV's recent Robin Hood series interest has never been so high."
A statement from Tesco, which leases the property from another firm and sublets it to Tales of Robin Hood, said: "We have been in discussions with Mr Walker about the future since the summer of 2008 and have always made it clear that the instalment of rent - due on 25 December - must be paid.
"We remain available to discuss the situation with Mr Walker but on the understanding that the next rent instalment will be paid on time."
The public will be able to visit the exhibit for free from Saturday 27 December to Sunday 4 January.