The Treasury is expected to respond by tomorrow to a financial rescue plan to keep open the London Lighthouse centre for HIV/AIDS until its expected sale in September.

The plan was drawn up jointly last week by Kensington & Chelsea and Westminster health authority and managers at the Lighthouse charity after Treasury officials demanded to see a business case to justify an interest-free loan of£715,000 to keep residential services open.

The sale of the building was triggered by the withdrawal of£1.7m of NHS funding for residential services at the Lighthouse. Chief executive Susie Parsons told a packed HA meeting last week that 15 of the 16 residential beds were occupied.

The HA accepted that the decision to sell the Lighthouse building was irreversible after a long discussion of various options and despite an emotional plea from Mark Silas, a representative of the recently formed Save the London Lighthouse campaign.

Mr Silas, who uses a wide range of Lighthouse services, told the meeting: 'A lot of us feel that the garden is a very sacred place. The building is sacred. It is more than just its services. There are 700 people whose ashes are in the garden.'

But HA chief executive John James said it was too late to rescue the building. 'If we had had a year to plan it, it would have been right to try for a longer period to find alternative use for the building, ' he told the meeting. 'The plain fact is, in my judgement, it is simply not possible to stop the clock. The receivers are waiting round the door.'

Mr James, who previously ruled out formal consultation over the proposals, suggested that the HA and the local community health council should form a joint working group to develop proposals for future provision of residential services for residents with AIDS. CHC chair Judith Blakeman said she would seek legal advice and report to the next CHC business meeting.

Mr Silas told the Journal after the meeting: 'We believe there is no final solution until the Lighthouse is actually closed. We are going to save the building, save the service.'