Open Question: Do banks have the right?

My father died 2 weeks ago and he had a barclays personal loan in his name. Is my mother liable to pay the loan off for him? The account was in joint names but my father;s name has now been removed but their is about 5,000 left of the loan to pay off. Can they force my mum to pay this off?
no, i think everyone is missing the point….the currant account was in both of their names, but the loan account was in my fathers name only…