Smith v Cosworth Casting Processes Ltd  EWCA Civ 1099
Permission to appeal guidance "(1) The court will only refuse leave if satisfied that the applicant has no realistic prospect of succeeding on the appeal. This test is not meant to be any different from that which is sometimes used, which is that the applicant has no arguable case. Why however this court has decided to adopt the former phrase is because the use of the word "realistic" makes it clear that a fanciful prospect or an unrealistic argument is not sufficient. (2) The court can grant the application even if it is not so satisfied. There can be many reasons for granting leave even if the court is not satisfied that the appeal has any prospect of success. For example, the issue may be one which the court considers should in the public interest be examined by this court or, to be more specific, this court may take the view that the case raises an issue where the law requires clarifying."