18. (1) This section applies to an employee whose contract of employment operates to require the employee to make himself or herself available to work for the employer in a week—

(a) a certain number of hours ("the contract hours"),

(b) as and when the employer requires him or her to do so, or

(c) both a certain number of hours and otherwise as and when the employer requires him or her to do so,

and the requirement is not one that is held to arise by virtue only of the fact, if such be the case, of the employer having engaged the employee to do work of a casual nature for him or her on occasions prior to that week (whether or not the number of those occasions or the circumstances otherwise touching the engagement of the employee are such as to give rise to a reasonable expectation on his or her part that he or she would be required by the employer to do work for the employer in that week).

(2) In a contract for a certain number of hours of work referred to in paragraphs (a) and (c) of subsection (1), the number of hours concerned shall be greater than zero.

(3) Notwithstanding subsection (1), subsection (2) shall not apply to—

(a) work done in emergency circumstances, or

(b) short-term relief work to cover routine absences for that employer.

(4) If an employer does not require an employee to whom this section applies to work for the employer in a week referred to in subsection (1)—

(a) in a case falling within paragraph (a) of that subsection, at least 25 per cent of the contract hours, or

(b) in a case falling within paragraph (b) or (c) of that subsection where work of the type which the employee is required to make himself or herself available to do has been done for the employer in that week, at least 25 per cent of the hours for which such work has been done in that week,

then the employee shall, subject to this section, be entitled—

(i) in a case where the employee has not been required to work for the employer at all in that week, to be paid by the employer the pay he or she would have received if he or she had worked for the employer in that week whichever of the following is less, namely—

(I) the percentage of hours referred to in paragraph (a) or (b), as the case may be, or

(II) 15 hours,

(ii) in a case where the employee has been required to work for the employer in that week less than the percentage of hours referred to in paragraph (a) or (b), as the case may be (and that percentage of hours is less than 15 hours), to have his or her pay for that week calculated on the basis that he or she worked for the employer in that week the percentage of hours referred to in paragraph (a) or (b), as the case may be,

and the minimum payment shall be calculated as 3 times the national minimum hourly rate of pay within the meaning of the National Minimum Wage Acts 2000 and 2015 or 3 times the minimum hourly rate of remuneration established by an employment regulation order, for the time being in force, on each occasion that this occurs.

(5) Subsection (4) shall not apply—

(a) if the fact that the employee concerned was not required to work in the week in question the percentage of hours referred to in paragraph (a) or (b) of that subsection, as the case may be—

(i) constituted a lay-off or a case of the employee being kept on short-time for that week, or

(ii) was due to exceptional circumstances or an emergency (including an accident or the imminent risk of an accident), the consequences of which could not have been avoided despite the exercise of all due care, or otherwise to the occurrence of unusual and unforeseeable circumstances beyond the employer’s control,

or

(b) if the employee concerned would not have been available, due to illness or for any other reason, to work for the employer in that week the said percentage of hours.

(6) The reference in subsection (4)(b) to the hours for which work of the type referred to in that provision has been done in the week concerned shall be construed as a reference to the number of hours of such work done in that week by another employee of the employer concerned or, in case that employer has required 2 or more employees to do such work for him or her in that week and the number of hours of such work done by each of them in that week is not identical, whichever number of hours of such work done by one of those employees in that week is the greatest.

(7) References in this section to an employee being required to make himself or herself available to do work for the employer shall not be construed as including references to the employee being required to be on call, that is to say to make himself or herself available to deal with any emergencies or other events or occurrences which may or may not occur.

(8) Nothing in this section shall affect the operation of a contract of employment that entitles the employee to be paid wages by the employer by reason, alone, of the employee making himself or herself available to do, at the times and place concerned, the work concerned.]