Closing a long-running mental health drop-in centre in Hounslow could lead to suicides, campaigners have warned.
The Number 10 Project has been described as a "vital lifeline" for more than 500 users who meet and take part in activities there throughout the week.
But the centre in School Road, just off Hounslow High Street, is set to close to make way for an expanded primary school and new homes .
John Viner, chairman of the School Road Management Committee, which runs the user-led service, has warned of dire consequences if the closure goes ahead.
"This is the borough's last remaining drop-in centre for people with mental health problems," he said.
"There were at least two suicides directly linked to the closure in 2012 of Canal House (a former mental health centre in Brentford ), which had 140 members.
"If this closes there will be suicides. This is a vital lifeline for some of Hounslow’s most vulnerable adults and many users see this as their extended family or in some cases their only family."
Hundreds sign petition to save centre
Mr Viner has created an online petition to save the "life-saving, life-affirming" service, which has more than 250 signatures.
getwestlondon reported earlier this year how a "vital" mental health centre in Harrow was saved after more than 1,800 people signed a petition opposing its closure.
The Number 10 Project hosts activities seven days a week, including yoga classes, cookery lessons and theatre sessions.
It caters for people with a wide spectrum of mental health problems, including a number of women traumatised by the Somali Civil War, rough sleepers and many users with drug and alcohol abuse problems.
The service is provided by EACH (Ethnic Alcohol Counselling in Hounslow) for Hounslow Council , which owns the building.
Mr Viner said service users were told by the council last summer that the existing building was to be demolished but were assured alternative premises would be found.
Centre scheduled to close in less than two months
He said they were told this June that no other site was available and the service, which has been running for 16 years, would close from August 31 so demolition work could begin.
He told getwestlondon that a new home for the neighbouring Hounslow Music Service was being built as part of the new development but there was no space for the Number 10 Project.
The centre is a safe place for people with mental health problems to socialise and support one another through any difficulties.
It provides hot meals, and in the winter offers rough sleepers sanctuary from the cold, remaining open throughout the winter.
Council 'taking steps to protect valued and important resource'
A spokesperson for Hounslow Council said no decision had yet been made to demolish 10 School Road, with a planning application for an expanded Hounslow Town Primary School and 250 new homes yet to be submitted.
But the council said it was expected the building would need to be vacant by September to enable preparatory works to begin so the new school building could be completed in time to meet the demand for school places.
The council said four alternative venues for the Number 10 Project had been considered, but in each case the rent was too high to be viable, and it was continuing to search for a suitable property.
The council said it had worked with EACH, and council officers had attended consultation meetings with many of those who use the service.
"From this consultation, we are aware it is a much valued and important resource," said a council spokesperson.
"Steps are being taken, in discussion with West London Mental Health Trust, to determine specific needs so that the important functions are being delivered to 10 School Road and can continue to be delivered in an alternative provision."
'Closure could add to strain on police and health service'
Mr Viner said the service costs around £5 a day per user to run - a fraction of the £380 a day he said it cost per inpatient at Lakeside Mental Health Unit in Isleworth.
He said many people were referred to the Number 10 Project by West London Mental Health Trust (WLMHT), which runs Lakeside, and closing the centre would put a greater strain on the trust.
He also warned that shutting the centre would lead to an increase in street drinking and drug-taking, adding to the workload of local police.
Sandra Machado, director of EACH, said: "We are in discussions with the council and are looking to explore other options to protect some of the services."
A WLMHT spokeswoman said it would not be appropriate to comment as it does not provide the service.