This section extends the powers conferred on beneficiaries by Section 19 to deal with the case where a trustee is incapable of exercising his functions as trustee as a result of mental disorder. Although there is no definition of mental disorder, it presumably has the same reason as in the Mental Health Act 1983 -- see sub-section (2)(c).

As in the case of Section 19, the power only arises where all the persons beneficially interested under the settlement are of full age and are together absolutely entitled to the trust fund (and the settlement does not provide that the section is not to apply); it will therefore not apply if the trustee himself is a beneficiary under the settlement. It also only arises when there is no person who is both willing and able to appoint a new trustee in place of the mentally disordered person under the powers conferred by Section 36(1) of the Trustee Act 1925 -- sub-section (1)(b).

When the Section does apply the beneficiaries can give the trustee's receiver, an attorney acting for the trustee under a registered Enduring Power of Attorney, or a person "authorised for the purpose by the authority having jurisdiction under Part VII of the Mental Health Act 1983" a written direction to appoint the person specified in the direction as a new trustee. (For the form of the direction see Section 21 below.)

This is an odd provision. It does not specify that the persons to whom the direction is given shall have the power to appoint a new trustee, or whether he can act alone or together with the other trustees. There are no provisions corresponding to Section 19(3). The person authorised under the 1983 Act is presumably a person authorised by the Judge or the Master of the Court of Protection.