"All reasonable endeavours" obligations were discussed in Jet2.com v Blackpool Airport Ltd [2011] EWHC 1529 (Comm).  In the Jet2.com case, the judge emphasised that the extent of the obligation is ‘simply a question of fact’ and that its meaning should be determined by reviewing the terms of the contract rather than ‘other cases’.  This could result in uncertainty and to avoid this the parties may prefer to clarify the extent of the obligation in the relevant clause.