(1) Subject to the provisions of this section and section 18, a person who has attained the age of 18 years and who considers that his or her capacity is in question or may shortly be in question may appoint a suitable person who has also attained that age to jointly make with the first-mentioned person one or more than one decision on the first-mentioned person's personal welfare or property and affairs, or both, in compliance with this Part, regulations made under section 31 and specifications made under section 31A.

(1A) A person in relation to whom a decision-making representation order was made in circumstances where section 38(1)(a) or section 55(4) applied may appoint a co-decision-maker in accordance with this section, and this Part and the regulations and specifications made thereunder shall apply to that appointment with any necessary modifications.

(2) A person is suitable for appointment as a co-decision-maker if he or she -

(a) is a relative or friend of the appointer who has had such personal contact with the appointer over such period of time that a relationship of trust exists between them, and