Opinion of Advocate General Emiliou delivered on 1 December 2022.

• Jurisdiction: European Union
• Celex Number: 62020CC0660
• ECLI: ECLI:EU:C:2022:953
• Date: 01 December 2022
• Court: Court of Justice (European Union)

Provisional text

OPINION OF ADVOCATE GENERAL

EMILIOU

delivered on 1 December 2022(1)

Case C‑660/20

MK

v

Lufthansa CityLine GmbH

(Request for a preliminary ruling from the Bundesarbeitsgericht (Federal Labour Court, Germany))

(Reference for preliminary ruling – Social policy – Principle of non-discrimination of part-time workers – Pilots – Principle of pro rata temporis – Higher level of remuneration for additional flying duty hours beyond a monthly threshold – Threshold that is identical for full-time and part-time pilots)

I. Introduction

1. MK is a pilot employed on a part-time basis (90% of full-time working hours) by Lufthansa CityLine GmbH. Due to the specific nature of the profession, his part-time employment consists in him being granted additional days of leave per year. However, there is no reduction in his number of flying duty hours during his workdays, on which he thus works as if he were a full-time pilot. In terms of remuneration of those flying duty hours, three increased rates of salary apply for the hours worked beyond three progressive thresholds of monthly flying duty hours. Those same thresholds apply uniformly to all the pilots employed by the defendant, irrespective of whether they are employed on a full-time or a part-time basis.

2. MK took the view that the application of those thresholds results in him being treated less favourably than a comparable full-time worker within the meaning of the German legislation which transposed the Framework Agreement on part-time work (‘the Framework Agreement’). (2) Hence, he brought an action against the defendant seeking the difference between the pay that he received and the pay he claims that he should have received, were the thresholds at issue lowered proportionally in relation to his part-time employment.

3. That action was upheld at first instance. It was, however, subsequently denied on appeal. The Bundesarbeitsgericht (Federal Labour Court, Germany), seised with MK’s appeal on a point of law, wonders whether the uniform thresholds in question indeed lead to a situation in which MK is being treated less favourably within the meaning of the Framework Agreement. In view of the Court’s case-law, and considering the doubts that have emerged on that issue in the national case-law, the referring court is uncertain about the proper test for determining whether there is an unequal treatment of a part-time employee such as MK. If the rules at issue were indeed to result in MK being treated less favourably, the referring court also seeks clarification on whether such treatment is justified by the objective pursued by those rules, namely, to compensate for a particular workload.

II. Legal framework

A. European Union law

4. Clause 4 of the Framework Agreement concerns the principle of non-discrimination. Its paragraphs 1 and 2 read as follows:

‘1. In respect of employment conditions, part-time workers shall not be treated in a less favourable manner than comparable full-time workers solely because they work part time unless different treatment is justified on objective grounds.

2. Where appropriate, the principle of pro rata temporis shall apply.’

B. German law

5. Paragraph 134 of the Bürgerliches Gesetzbuch (German Civil Code; ‘the BGB’) provides that any legal act which infringes a statutory prohibition is void.

6. Paragraph 4(1) of the Gesetz über Teilzeitarbeit und befristete Arbeitsverträge (Law on part-time work and fixed-term contracts; ‘the TzBfG’) provides that ‘a part-time worker shall not be treated in a less favourable manner than a comparable full-time worker on account of working on a part-time basis, unless different treatment is justified on objective grounds. The part-time worker shall receive remuneration or another pro rata benefit, the extent of which shall at least correspond to the proportion of his or her work as compared with that of a comparable full-time worker’.

III. Facts, national proceedings and the questions referred

7. MK has been employed by the defendant as a pilot and first officer since 2001. As of 2010, he has been working on a part-time basis, meaning that his working hours have been reduced to 90% of full-time working hours. Accordingly, his basic remuneration has been reduced by 10%.

8. In practical terms, MK’s part-time employment consists in him being granted an additional 37 days of leave per year. However, there is no reduction in his number of flying duty hours during his workdays.

9. According to the applicable collective wage agreements for the defendant’s cockpit crew, the flight duty time is one component of the working time. (3) A worker receives remuneration for additional flying duty hours (Mehrflugdienststundenvergütung), on top of his or her basic remuneration, if he or she has worked a certain number of flying duty hours in a month and has thereby exceeded (triggered) the thresholds for the higher level of remuneration. For that purpose, the collective agreements establish three different hourly rates. These are used to calculate remuneration if the worker has worked respectively 106, 121 and 136 monthly flying duty hours on short-haul flights. Lower trigger thresholds of 93, 106 and 120 flying duty hours per month apply to long-haul flights. The collective agreements make no provision, in the case of workers who work part-time, for reduction of those thresholds in line with their part-time percentage.

10. To determine MK’s monthly remuneration for additional flying duty hours, the defendant calculates an individual trigger threshold that takes into account MK’s part-time work. For flying duty hours which MK works in excess of his individual trigger threshold, he receives the hourly pay determined on the basis of his basic remuneration. It is only when his flight duty time exceeds the trigger thresholds that he receives a higher level of remuneration.

11. MK brought an action against the defendant, seeking payment of the difference between the remuneration already paid and the higher level of remuneration for additional flying duty hours on the basis of trigger thresholds lowered proportionally to his part-time factor.

12. Although the Arbeitsgericht München (Labour Court, Germany) upheld that action, it was later dismissed by the Landesarbeitsgericht München (Higher Labour Court, Germany).

13. The Bundesarbeitsgericht (Federal Labour Court), seised of an appeal on a point of law lodged by MK, observes that the thresholds triggering the higher level of remuneration for additional flying duty hours apply in a uniform manner to full-time and part-time workers. That court questions whether such circumstances result in part-time workers being treated less favourably than comparable full-time workers within the meaning of Paragraph 4(1) of the TzBfG. If there is indeed a less favourable treatment with regard to pay, that court notes that it will be necessary to examine whether it is justified by an objective ground allowing for a deviation from the principle of pro rata temporis.

14. Observing that Paragraph 4(1) of the TzBfG transposes Clauses 4.1 and 4.2 of the Framework Agreement into national law, the referring court is unsure about the proper test for determining whether there is unequal treatment. More specifically, that court is uncertain as to whether the assessment should be based on the methodology used in the judgments in Elsner-Lakeberg (4) and in Voß (5) which involve, in its view, an examination of the various components of remuneration or whether the assessment should rather be guided by the consideration of the overall pay as decided, according to the referring court, in the judgment in Helmig. (6) The referring court indicates that the use of the latter method will lead to the conclusion that the rules at issue do not involve any difference in treatment. However, the opposite is true if the former method were to be applied. Under that approach, the provisions at issue will be upheld only if the objective pursued by them, namely to compensate for a particular workload, can be considered to be an objective ground, within the meaning of Clause 4.1 of the Framework Agreement, capable of justifying an inequality of treatment.

15. It is in those circumstances that the Bundesarbeitsgericht (Federal Labour Court) decided to stay the proceedings and to refer the following questions to the Court of Justice for a preliminary ruling:

‘(1) Does a national statutory provision treat part-time workers in a less favourable manner than comparable full-time workers within the meaning of Clause 4.1 of [the Framework Agreement] if it permits additional remuneration for part-time and full-time workers to be uniformly contingent on the same number of working hours having been exceeded, and therefore allows account to be taken of the overall remuneration, and not of the component of the remuneration that comprises the additional remuneration?

If Question 1 is answered in the affirmative:

(2) Is a national statutory provision which allows an entitlement to additional remuneration to be made conditional on the same number of working hours being exceeded uniformly in the case of both part-time and full-time workers compatible with Clause 4.1 and the principle of pro rata temporis in Clause 4.2 of [the Framework Agreement] if the purpose of the additional remuneration is to compensate for a particular workload?’

16. Written observations have been submitted by MK, the defendant, the German Government and the European Commission. Those parties, together with the Danish, Polish and Norwegian Governments presented oral argument at the hearing that took place on 21 September 2022.

IV. Analysis

17. By its first question, the referring court wonders, in essence, whether provisions such as the ones at issue, set out in collective agreements, bring about unequal treatment between part-time and full-time employees given that both categories of employees must reach the same...