Beaumont Healthcare will be the fifth care provider to hand back contracts to Cambridgeshire County Council this year. It has left clients and staff facing looming uncertainty.
The firm has 150 clients through Cambridgeshire County Council, another 15 through Central Bedfordshire Council and eight more in the Sandy and Biggleswade area who are self-funded.
In a letter to clients sent on 25 October, seen by the BBC, the company said "the operation has become unsustainable in the last recent months".
Care is due to stop on 23 November, sparking concerns for vulnerable clients, some of whom rely on multiple daily visits.
'Dreading break in care'
Tamsin Olney, from Bythorn, near Huntingdon, has carers to help her look after her 19-year-old son Oscar who has complex needs and disabilities and is non-verbal.
Ms Olney, 46, said it could take up to six months for carers to get to know Oscar's body language and vocalisations.
It previously took months for the council to find an agency able to take on his needs and Ms Olney said she was "dreading a break in care".
She said: "Oscar is severely disabled with complex health needs. He's not often well enough to leave the house and needs a lot of support to get through the day and to get the most out of the day.
"We've been really lucky and had some super carers work with Oscar and now it's all going to stop," she said.
"Looking after Oscar is really demanding; it's a non-stop job. When carers are not here there's no let-up."
She said she was worried about the "ripple effect" of the agency shutting, putting pressure on not just her family but also other clients and the carers who faced losing their jobs.
Ms Olney said clients "deserved more explanation and more notice", as well as recognition of the impact it would have.
'Is this real?'
TJ Jimenez, a senior healthcare worker and one of Oscar's carers, has worked for the company for 18 months but said communication about the closure had not been clear.
"It was very shocking. I received a phone call from the office and told we had 28 days and the company is closing. So at first it doesn't sink in yet, [I thought] 'Is this really real?'"
Staff then received an email but it gave no specifics, and getting information from the company's office had been difficult, he said.
"We're in a very difficult situation because we have to find jobs, especially as I'm a family man. I need continuity of income," he said.
Mr Jimenez also worries for clients such as Oscar who need specialised care and rely on carers being able to read their body language and cues.
"I'm attached to my client and don't want to leave them just like that. It's really devastating for all of us," he said.
"I'm worried about him because it's not easy to train new people and people might think that he's ok but maybe he's not and training new people will be a big adjustment for my client."
He hopes a new provider will be "able to give the proper standard of care and love he deserves".
'Terrifying for staff'
Public service union Unison said it was "supporting a large number of members who work for Beaumont Healthcare", many of whom were in the UK on work visas.
Cambridgeshire branch secretary Robert Turner said was "terrible" that more than 100 staff would need to search for new jobs.
"It's particularly terrifying for staff on work visas and their families who could be losing their jobs and homes if they can't find suitable new employers," he said.
"That would be awful for the workers and their families as well as dire for a social care sector already struggling with a chronic workforce shortage.
"And it should send shockwaves throughout Cambridgeshire and the whole country. Beaumont going bust isn't a one-off, it's symptomatic of a wider crisis in our profit-driven, under-resourced social care system."
He said the council needed to do everything it could to help people find new carers and staff to find new jobs.
'Care can't stop'
Richard Howitt. the Labour councillor who chairs Cambridgeshire County Council's adults and health committee, said: "We're talking about mainly elderly people who have carers coming in and out, sometimes several times a day to get out of bed, to use the loo, to be washed, to be fed.
"That care can't stop. It has to continue and that's why Cambridgeshire County Council is working day and night to ensure the service continues for each and every person affected.
"Sadly, this is the fifth care provider in the last year that has handed back their contract. The financial pressure on the sector as a whole is enormous. The lack of funding nationally people hear about, this is what it means in practice."
He said the council was working to try to ensure that the carers many vulnerable clients trusted and relied on were transferred to new providers to allow continuity of care.
Mark Smith, Central Bedfordshire Council's cabinet member for adult social care, said all customers and their families had been contacted and work was ongoing to find alternative provision, hopefully by the end of next week.
A spokesman for St Neots-based Beaumont Healthcare, which has been operating since 1996, said it was "with great sadness that we have now to end our contracts as it has become unsustainable within the financial constraints to continue".
He said it had worked with thousands of families but that the region has "always had significant difficulty in recruitment of sufficient care staff".
The company said it met this challenge by recruiting thousands of carers from overseas who "have contributed very significantly into the care sector, locally and nationally".
It said it was working to ensure a "safe handover of care to other care providers" and assisting staff to transfer to other agencies and find new work.