The future of a much-loved community gym in Hampstead hangs in the balance after the council set a four-month deadline for the sale of the property.

Camden Council’s cabinet met at Camden Town Hall last night to discuss the future of The Armoury, a charity-run gym in Pond Street, which the council wishes to sell as part of the Community Investment Programme (CIP).

At the meeting, the cabinet agreed that the facility is “surplus to requirements” and gave the Jubilee Hall Trust (JHT), which runs the gym, four months to agree the terms of a 50-year lease on the building.

If the trust fails to agree a deal with the council before the four-month deadline, the gym will be sold on the free market to a private developer.

Cllr Theo Blackwell, cabinet member for finance, told the meeting: “The decision on this paper isn’t to sell The Armoury tomorrow or the next day but to continue negotiations with [the trust] and to try and find a win, win [situation] for the community which goes some way to meeting the council’s massive capital problems.”

The public gallery at last night’s meeting was packed with supporters of the gym brandishing signs reading “Save The Armoury”.

Under JHT, the gym offers discounted rates to local residents as well as accommodating patients and staff from the Royal Free Hospital.

In 2010, The Armoury did not renew its lease on 25 Pond Street and since then the council, which owns the property, has looked to offload the building as part of the CIP, under which some council-owned buildings will be sold and the profit spent on schools and council housing.

The council is offering to sell the premises to the trust or to extend the lease at a substantially higher price than the previous one.

However, the £1.5million sale price is more than double the amount the charity is prepared to offer and the trust believe the community gym is simply not worth that amount.

Last night, Cllr Blackwell added: “We have a duty to protect the taxpayer’s assets here in Camden. We have been prepared to be very flexible, offering a substantially reduced rate on the lease for the first 12 years to [help the JHT] deal with the capital costs.”

Hampstead Town councillor Linda Chung (Liberal Democrat), a board member of the JHT and a regular user of the gym, addressed the cabinet last night.

She said: “We in Camden should be proud of this gym. It’s good for mental health and good for equalities and social mix. It stops community breakdown.

“Please don’t regard it just as a building open to development. You have the power to save our gym and let it carry on its good work.”