Ten jobs could go at the HMS Caroline floating museum in Belfast as the government's Coronavirus Job Retention Scheme runs out.
The Department for the Economy has said it had offered to pay salaries up until the end of this year but that no agreement has been reached.
The museum on board the First World War vessel is run by the National Museum of the Royal Navy (NMRN).
But the ship has been shut since the start of lockdown - with the HMS Caroline Preservation Society warning it is at risk of contamination and should be towed to Portsmouth for safety.
The NMRN developed the ship in 2012 as a maritime heritage visitor attraction, funded by the National Lottery Heritage Fund and Tourism NI, within the economy department.
But the present agreement expired on June 30, with no new funding model, operational agreement and operator in place.
The Department for the Economy said yesterday: "HMS Caroline (HMSC) was closed to the public on March 17 due to the Covid-19 crisis. Following discussions with the NMRN... the Minister for the Economy decided to extend the period of closure until December 31.
"Visitor numbers to HMSC have been disappointing since its opening in 2016 and this has resulted in operational deficits.
"The department has been concerned about these deficits for some time and has been working closely with NMRN to attempt to reduce deficits and ensure greater value for the use of public funds.
"NMRN agreed to provide an oversight and maintenance role during the period of temporary closure and the department confirmed that it would meet agreed associated costs.
"The minister also agreed to cover the salary costs of HMSC staff until December 31, following the cessation of the Job Retention Scheme.
"However, the legal terms to underpin this period have not yet been agreed with NMRN."
The department said it was working on options for the ship's long-term future.
The NMRN said: "With no agreement between NMRN and the DfE in place, we have had to make the hugely regrettable decision to make our team there redundant on the October 31 in conjunction with the end of the Coronavirus Job Retention Scheme."
Industries including events are expected to make large numbers of staff redundant as employers do not have the money to contribute to salaries under the job support scheme.
BWUH Ltd, the company behind Belfast's Waterfront and Ulster halls, said it would be stopping payments of up to 140 casual team members who were paid under the CJRS.
However, it said permanent staff would transfer to a job support scheme for businesses which are unable to open.