Around two in five of the 119 trainee fast jet pilots in the RAF's pipeline are on holdover between courses or waiting to start their operational conversion unit, fresh MoD figures show.

A holdover is the term used by the RAF for a trainee pilot who has finished one stage of the syllabus but is not yet able to start the next, usually because there is no aircraft, instructor or course place available, with those pilots often filling time on ground tours and other duties while losing flying currency and costing the service money.