5.—(1) For the purposes of this Part, an employee is a comparable permanent employee in relation to a fixed-term employee if—

(a) the permanent employee and the relevant fixed-term employee are employed by the same employer or associated employers and one of the conditions referred to in subsection (2) is satisfied in respect of those employees,

(b) in case paragraph (a) does not apply (including a case where the relevant fixed-term employee is the sole employee of the employer), the permanent employee is specified in a collective agreement, being an agreement that for the time being has effect in relation to the relevant fixed-term employee, to be a type of employee who is to be regarded for the purposes of this Part as a comparable permanent employee in relation to the relevant fixed-term employee, or

(c) in case neither paragraph (a) nor (b) applies, the employee is employed in the same industry or sector of employment as the relevant fixed-term employee and one of the conditions referred to in subsection (2) is satisfied in respect of those employees,

and references in this Part to a comparable permanent employee in relation to a fixed-term employee shall be read accordingly.

(2) The following are the conditions mentioned in subsection (1)—

(a) both of the employees concerned perform the same work under the same or similar conditions or each is interchangeable with the other in relation to the work,

(b) the work performed by one of the employees concerned is of the same or a similar nature to that performed by the other and any differences between the work performed or the conditions under which it is performed by each, either are of small importance in relation to the work as a whole or occur with such irregularity as not to be significant, and

(c) the work performed by the relevant fixed-term employee is equal or greater in value to the work performed by the other employee concerned, having regard to such matters as skill, physical or mental requirements, responsibility and working conditions.