15.—(1) An employer shall not penalise an employee—

(a) for invoking any right of the employee to be treated, in respect of the employee’s conditions of employment, in the manner provided for by this Part, or

(b) for having in good faith opposed by lawful means an act which is unlawful under this Act, or

(c) for refusing to accede to a request by the employer to transfer from performing—

(i) full-time work to performing part-time work, or

(ii) part-time work to performing full-time work,

or

(d) for giving evidence in any proceedings under this Act or giving notice of his or her intention to do so or to do any other thing referred to in paragraph (a), (b) or (c).

(2) For the purposes of this section, an employee is penalised if he or she—

(a) is dismissed, suffers any unfavourable change in his or her conditions of employment or any unfair treatment (including selection for redundancy), or

(b) is the subject of any other action prejudicial to his or her employment,

but, where any such action with regard to the employee is in respect of the matter referred to in subsection (1)(c), that action shall not constitute a penalisation of the employee if both of the following conditions are complied with—

(i) having regard to all the circumstances, there were substantial grounds both to justify the employer’s making the request concerned and the employer’s taking that action consequent on the employee’s refusal, and

(ii) the taking of that action is in accordance with the employee’s contract of employment and the provisions of any other enactment of the kind to which section 20(2) applies.

(3) If a penalisation of an employee, in contravention of subsection (1), constitutes a dismissal of the employee within the meaning of the Unfair Dismissals Acts, 1977 to 1993, relief may not be granted to the employee in respect of that penalisation both F3[under Part 4 of the Workplace Relations Act 2015] and under those Acts.

(4) In this section—

“full-time work” means work which, if it were performed, would result in the person performing it being regarded as a full-time employee for the purposes of this Act;

“part-time work” has the same meaning as it has in section 13.