An urgent £1 million grant is needed to secure the future of the Citizens Theatre.
A £21.5m scheme will revamp the Southside theatre, building an “theatrical, creative and cultural hub” for the surrounding communities.
But a funding gap has been identified which, unless addressed quickly, could see funders pull out of the project.
Glasgow councillors are being urged to back handing over £1m to keep the work on track.
The Category B listed theatre, which is a council-owned asset leased to Citizens Theatre Ltd, closed in June 2018 for redevelopment.
There is currently a gap between the estimated project cost and confirmed funding, with more than £20m, including a £5m commitment from Glasgow City Council, already secured.
Richard Brown, the Council’s Executive Director of Regeneration and the Economy, said: “The redevelopment and restoration will be the first comprehensive renovation in the building’s 140 years.
“It will secure the future of an ageing and vulnerable building as an essential theatrical, creative and cultural hub for both the city and local communities.
“The redevelopment is a beacon project in the Laurieston regeneration area and is an urgent response to a deteriorating building and to the Citizens’ ambition to partner in the social and economic regeneration of the local community.”
He added: “Following a number of meetings, some of the funders have committed to increasing their contribution to assist in bridging the funding gap.”
His report to councillors states an extra £1m would close the funding gap to an acceptable level, allowing the project to progress.
It would also “lock down” other funders’ increased offers.
The total £21.5m cost includes contingencies of £1.4m. This is based on achieving engineering and re-tendering savings of £1.03m.
Mr Brown said: “While the additional £1m from the Council would close the funding gap to a level that would allow the project to proceed, the decision to progress with the works is not without an element of risk, given the current predicted project cost being dependent upon an additional £1.03m of value engineering and retendering savings being realised.
“However, the risk of not achieving this cost saving balanced against the risk of not progressing the works as soon as possible is seen by all of the funders as the lesser risk.
“Any further delay in progressing the works will see the possibility of funders pulling out of the project altogether (leading to a total collapse of the funding package), the landed tenders becoming out of date, and the significant risks associated with construction based inflation.”
Other funders in the project include the Heritage Lottery Fund, Creative Scotland, Historic Environment Scotland and the Scottish Government.