William Burdett-Coutts, the artistic director of Assembly Theatre, yesterday expressed concerns about the city council's plans to give over the front of the building to retail space.
But Councillor Steve Cardownie, the city's festival and events champion, said: "I am disappointed that Bill Burdett-Coutts has chosen to embark on this misguided campaign. This is pure scaremongering.
"In contrast to their alarmist and misleading claims, the refurbishment will in fact guarantee the building's future as one of the most sensational events venues in the city."
He also said a suggestion that Assembly Theatre could take on the running of the venue year-round was "unworkable".
Councillors are due to pass a verdict on whether to give consent tomorrow.