A multimillion-pound project to reopen a Grade II listed lido is in doubt due to the effect of coronavirus on construction.
Work to restore Broomhill Pool in Ipswich, costing £7.25m, was due to start in the spring, but was postponed because of lockdown.
The Heritage Lottery Fund was waiting to hear more about proposals before making a decision about its funding.
Campaigners said the news was "heartbreaking".
Hosting 2,000 visitors a day when it opened in the late-1930s, the pool has been closed since 2002.
The firm behind the restoration, Fusion Lifestyle, said it had no update on when work could begin.
The project to reopen the lido is being funded in part by the National lottery Heritage Fund and Ipswich Borough Council.
A spokeswoman for the Heritage Lottery Fund, which has committed £3.4m to it, but has so far only handed over a smaller, undisclosed amount of that money, said it was in discussions with Fusion.
"We are waiting to hear the applicant's proposals for the future of the project. Once we understand how they want to progress, we can take a view on what our involvement in the project will be," she said.
The council said it "has a long-standing commitment" and still had £1.5m invested in the project.
Sally Wainman, who has campaigned to save the pool, hoped funding earmarked for the restoration would be protected until work could resume.
She said: "Everything was ready before the virus. Work was going to start this year.
"That is why it's so heartbreaking."
A spokesman for Fusion Lifestyle said: "We appreciate just how treasured Broomhill Pool is by the local community and we would love to have some news to share.
"Unfortunately, the effects of Covid have been far-reaching and... all works had to be put on hold."
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