In any circumstances relevant for the purposes of any provision of Part 2, a person discriminates against a person (“A”) who fulfils the condition in subsection (2) if—
(a) on the ground of the fulfilment of the condition, he treats A less favourably than he treats or would treat a person who does not fulfil the condition, or
(b) he applies to A a provision, criterion or practice which he applies or would apply equally to a person who does not fulfil the condition, but—
(i) which puts or would put persons fulfilling the condition at a particular disadvantage when compared with persons not fulfilling the condition, and
(ii) which puts A at that disadvantage, and
(iii) which he cannot show to be a proportionate means of achieving a legitimate aim.
The condition is that the person is—
(a) married, or
(b) a civil partner.
For the purposes of subsection (1), a provision of Part 2 framed with reference to discrimination against women is to be treated as applying equally to the treatment of men, and for that purpose has effect with such modifications as are requisite.