20.—(1) This section applies where—
(a)the act mentioned in section 9(1) is, or is done in the course of, the provision to P of treatment which is treatment with serious consequences (see section 21);
(b)section 19 (objection from nominated person) does not apply;
(c)the act—
(i)is resisted by P (see section 68); or
(ii)is done while P is subject to an additional measure (see section 23); and
(d)the circumstances are such as may be prescribed.
(2) Section 9(2) (protection from liability) applies to the act only if—
(a)the provision of the treatment to P is authorised; and
(b)the prevention of serious harm condition (as well as the conditions of section 9(1)(c) and (d), and any other conditions that apply under this Part) is met.
(3) Subsection (2)(a) does not apply where the situation is an emergency (see section 65).
(4) For the purposes of subsection (2)(a) the provision of the treatment to P is “authorised” if, at the time the act is done, there is in force an authorisation granted under Schedule 1 which authorises the provision of the treatment to P.
(5) See section 22 for the prevention of serious harm condition.