Judgment of the Court (Second Chamber) of 17 March 2021.#KO v Consulmarketing SpA.#Request for a preliminary ruling from the Tribunale di Milano.#Reference for a preliminary ruling – Social policy – Directive 1999/70/EC – Framework agreement on fixed-term work concluded by ETUC, UNICE and CEEP – Clause 4 – Principle of non-discrimination – Objective reasons justifying different treatment of fixed-term workers – Directive 98/59/EC – Collective redundancy – National legislation on the protection to be afforded to a worker dismissed as part of an unlawful collective redundancy – Application of a less advantageous protection system to fixed-term contracts concluded before its entry into force and converted into contracts of an indefinite duration after that date.#Case C-652/19.