(1) A person (A) discriminates against another (B) if A applies to B a provision, criterion or practice which is discriminatory in relation to a relevant protected characteristic of B's.
(2) For the purposes of subsection (1), a provision, criterion or practice is discriminatory in relation to a relevant protected characteristic of B's if—
(a) A applies, or would apply, it to persons with whom B does not share the characteristic,
(b) it puts, or would put, persons with whom B shares the characteristic at a particular disadvantage when compared with persons with whom B does not share it,
(c) it puts, or would put, B at that disadvantage, and
(d) A cannot show it to be a proportionate means of achieving a legitimate aim.
(3) The relevant protected characteristics are—
age;
disability;
gender reassignment;
marriage and civil partnership;
race;
religion or belief;
sex;
sexual orientation.