British Airways plc v Williams and others [2012] UKSC 43; [2012] WLR (D) 277

“Where a group of airline pilots’ claimed that their paid annual leave (as required by a European Aviation Directive) should include their regular supplementary allowances as well as their basic pay and, on a reference by the Supreme Court, the Court of Justice of the European Union had interpreted the Directive as requiring pay for annual leave to correspond to normal remuneration, assessed as being the average over a representative period of all remuneration save that intended exclusively to cover costs, the absence of a detailed domestic legislative scheme implementing the Directive’s requirements as to paid annual leave did not preclude an employment tribunal from making such an assessment.”

WLR Daily, 17th October 2012

Source: www.iclr.co.uk