My mother had the opportunity of buying her council house at a reasonable price, but because of her financial situation my husband pays the mortgage. If at any time my mother had to be taken into care will my husband have any claim on the house, or would it have to be sold to pay the fees?
The solution will probably be for your mother to make a declaration of trust stating that you and your husband are entitled to a share of the proceeds of sale, if and when the property is sold, to reflect your contributions in meeting the mortgage payments. Alternatively you could arrange a private mortgage. See a solicitor to discuss the various options. Your situation is not uncommon, but without safeguards there are risks for both parties.