If you were to become mentally incapacitated due to an illness or an accident, then without an LPA in place, the ONLY way your financial affairs can be managed is by an application being made to the court of Protection for a Deputyship Order.
The applicant must provide personal information about themselves, their family, their own finances, and the relationship with the person they wish to help care for.
This process costs a considerable amount of money and can take anything between 12 weeks and 10 months, by which time your finances could be seriously hampered. Even worse, the Judge will make the final decision as to who is appointed as your attorneys, and it may be possible they are not the person you had wished to manage your affairs.
The court may appoint a Panel Deputy (a retired Solicitor or Barrister who works for the Office of the Public Guardian) or a local authority.