A local social services authority shall appoint a sufficient number of approved social workers for the purpose of discharging the functions conferred on them by this Act.

No person shall be appointed by a local social services authority as an approved social worker unless he is approved by the authority as having appropriate competence in dealing with persons who are suffering from mental disorder.

In approving a person for appointment as an approved social worker a local social services authority shall have regard to such matters as the Secretary of State may direct.