A Tower Hamlets campaign group is fighting to save the former Jewish Maternity Hospital building in Whitechapel from demolition by developers.
Retired teacher and local historian Tom Ridge is spearheading a letter-writing campaign to preserve the building, which is more than a century old.
Arnold Wesker and Lionel Bart were among famous Jews born there.
The site in Underwood Road has been bought from Tower Hamlets Council by the Peabody Trust, which intends to build flats on it.
Mr Ridge wants the company to convert the hospital building into housing rather than demolish it.
He said 200 people were supporting his campaign and he was hoping to involve Jewish historical societies. English Heritage rejected his application for listed status on the ground that the building's architectural interest was not sufficiently high.
Known locally as "Mother Levy's hospital", it was founded by Alice Model, who was awarded an MBE in 1935 for her work in child welfare.
It was closed during the war and never returned to the Underwood Road premises, which were purchased in 1947 by the then Stepney Borough Council.
"It has an incredible history," Mr Ridge said. "It is a survivor of Jewish history in the East End. So much has been demolished already."
A Peabody Trust representative said: "We aim to submit a planning application in October and have already begun discussing our proposals with the planning department and local residents.
"We understand that this is a sensitive site and we are committed to working with all members of the local community in the development of this project."