Judgment of the Court (Second Chamber) of 3 June 2021.#K and Others v Tesco Stores Ltd.#Request for a preliminary ruling from the Watford Employment Tribunal.#Reference for a preliminary ruling – Social policy – Equal pay for male and female workers – Article 157 TFEU – Direct effect – Concept of ‘work of equal value’ – Claims seeking equal pay for work of equal value – Single source – Workers of different sex having the same employer – Different establishments – Comparison.#Case C-624/19.