Apologies for the delay this area of law is a rather unusual one.
The social workers owe your father a duty of care and will be aware of this. The emphasis is to try to allow people to live in their own homes where possible with care being provided by carers visiting the home rather than moving the person to a care home.
I would ask the social workers what care is to be provided which will allow you to decide whether you think it might work and object if you do not.
If you believe they are acting unreasonably you can use the formal council complaints procedure to get the decision reviewed
Your father has no right to insist on being in a care home but it must be done if it is the obvious option.