TUI Travel Plc, British Airways, Easyjet and IATA (Claimants) requested the British Civil Aviation Authority (Defendant) to confirm that it would not interpret the Regulation 261/2004/EC as imposing an obligation on air carriers to pay compensation in the event of delay. The Defendant has refused to provide this assurance, stating that it is bound to give effect to the ruling in Sturgeon.To sum up, claimants argue as follows:The plain wording of the Regulation which – as recognised by the Grand Chamber in IATA – is clear on its face. The Fourth Chamber in Sturgeon was wrong to give weight to the 15th recital to the Regulation; its reasoning on this point was explicitly rejected by the Grand Chamber in IATA;It is clear from the legislative history that there was no intention on the part of the Community legislature to require air carriers to pay compensation in the event of delay; the intention was to confine the payment of compensation to cases of denied boarding and certain cases of cancellation.The principle of proportionality compels the interpretation of the Regulation contended for by the Claimants;The principle of legal certainty compels the interpretation of the Regulation contended for by the Claimants and accepted by the Grand Chamber in IATA.The interpretation placed on the Regulation by the Fourth Chamber in Sturgeon is inconsistent with the Montreal Convention.Main question referred to the ECJ is therefore to reconsider whetherArticles 5-7 of Regulation (EC) No. 261/2004 are to be interpreted as requiring the compensation provided for in Article 7 to be paid to passengers whose flights are subject to delay within the meaning of Article 6, and if so in what circumstances?Case CO/6569/2010, TUI Travel Plc, British Airways Plc, Easyjet Airline Company Ltd and International Air Transport Association v The Cvil Aviation Authority