It is unlawful for an authority or a body which is empowered to confer, renew or extend an authorisation or a qualification that is needed for or facilitates the practice of a profession, the carrying on of a trade or the engaging in of an occupation to discriminate against a person on the ground of homosexuality--
(a) by refusing or failing to confer, renew or extend the authorisation or qualification,
(b) in the terms on which it is prepared to confer the authorisation or qualification or to renew or extend the authorisation or qualification,
(c) by withdrawing the authorisation or qualification or varying the terms or conditions upon which it is held.