You will need to get an order from the Court of Protection to deal with your father's affairs including your mother's will. Even if the will has not been executed, the council can't sell the house from under you.
Here's the government link with a lot of basic info. The application costs 400.00.
http://www.direct.gov...someoneelse/DG_176235
Age concern are also helpful
http://www.ageuk.org....on&nation=ageuk_en-GB
I would phone them on monday and get the info from the helpline BEFORE you talk to any social workers and be very careful what you agree to and what you sign.