Woolwich Grand Theatre looks set to be demolished to make way for housing, despite hundreds of objections.
A planning committee will decide the venue's fate on Tuesday (April 1), with numerous objectors expected to speak.
Ward councillor Coun John Fahy and Tory deputy leader Councillor Nigel Fletcher have come out against the plans, while an online petition to have it listed as an asset of community value has been signed by nearly 700 people.
And the Theatres Trust has criticised "the demolition and loss of a cultural asset without any reasoned justification."
The Art Deco former cinema building, which dates from the 1930s, had been turned around in recent years, but officers say the building is unattractive, much of it is not used by the theatre and a host of repairs are needed.