A trade union has called for Somerset County Council to rethink plans to outsource learning disability services to the private sector.
The council currently provides care in the home and respite support to about 900 vulnerable people.
Unison organiser Oliver Foster-Burnell said: "These vulnerable people are not commodities that should be put up for tender to the cheapest bidder."
The council has said the changes mean better choice and control for users.
A spokesman for the county council said: "The aim of the service review and the recommendation arising from it is to ensure high quality and sustainable learning disability services for the people of Somerset.
"Should the decision be made in the future to outsource services to the independent sector, staff affected by this would be protected by employment legislation."
The council has also said there are already a further 700 adults with learning disabilities who are getting care from the independent sector.
Jenny, a carer from Street, said: "It will make a big difference because they will have to answer to their shareholders or they have to at least make a profit if it is privatised.
"That money has to come from somewhere, so it can either come from quality of care or from staff in the way of wages and conditions being worse.
"If you have tired and knackered staff they won't be able to give their best, and service users deserve the best."
A more detailed business case is being prepared for the next stage in the review, the council has said.
The trade union is holding a conference in Taunton later to discuss the proposals.
Councillors are due to decide in a cabinet meeting on 2 May.