If the provision, practice or requirement puts people who belong to one of the grounds covered by the Acts at a particular disadvantage then the employer will have indirectly discriminated, unless the provision is objectively justified by a legitimate aim and the means of achieving that aim are appropriate and necessary.
Discrimination by association happens where a person associated with another person (belonging to a specified ground) is treated less favourably because of that association. Employers are liable for anything done by an employee in the course of his or her employment, unless the employer can prove that he or she took reasonably practicable steps to prevent the discrimination.
Section 22.1 of the Acts provides:
“(a) Indirect discrimination occurs where an apparently neutral provision puts persons of a particular gender at a particular disadvantage in respect of any matter other than remuneration compared with other employees of their employer.
(b) Where paragraph (a) applies, the employer shall be treated for the purposes of this Act as discriminating against each of the persons referred to, unless the provision is objectively justified by a legitimate aim and the means of achieving that aim are appropriate and necessary.”
Our State recognises the crucial role played by mothers of newly born children in our society. That’s a fundamental and the most basic tenet of any civilised society and that is why it is reflected in our law. This is a wonderful thing. Unless employers decide to ignore these rights.
Section 31 of the Acts has an identical provision in respect of other protected grounds.
In Bilka Kaufhaus GMBH v. Weber von Hartz  ECR 1607 the ECJ laid down a three tier test in determining whether the provision amounts to indirect discrimination. Do the measures chosen by the employer:
correspond to a real need on the part of the undertaking
are appropriate with a view to achieving the objectives pursued, and
are necessary to that end.
Once a prima facie case of indirect discrimination is established, it is then for the employer to demonstrate that the provision or requirement is objectively justified by a legitimate aim and the means of achieving that aim are appropriate and necessary.