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 on part-time work annexed to Directive 97/81/EC 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: 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 on part-time work annexed to Directive 97/81/EC if the purpose of the additional remuneration is to compensate for a particular workload?
MK – v – Lufthansa CityLine GmbH, reference lodged by the Bundesarbeitsgericht (Germany) on 4 December 2020