[holding answer 26 October 2009]: When movement is by commercial airline, as opposed to MOD charter or part-charter, class of travel is determined by the length of flight and the rank or civil service grade of the passenger. The majority of armed forces and civilian personnel will travel economy, tourist or budget class. Only when flights are longer than 2.5 hours will the passenger be entitled to travel club, executive, new economy, ambassador or premier economy. Two star officers and above and two star senior civil service and above, will mostly travel by club, executive, business, new economy, ambassador or premier. However, when this class of travel is not available, the flight is longer than 2.5 hours, and this is the only method of travel available to meet with designated service priorities, then the passenger is entitled to travel first class.
For rail and sea travel, most will travel by standard class. However, officers and civil servants who are Lieutenant Commander, Major, Squadron Leader, pay band C2 and above, travelling on duty, are entitled to first class travel.
Regardless of entitlement, though, all personnel are strongly encouraged to use the most economic means of travel at all times.