Mate, I know many NCA (or whatever we are called this week) who have applied for commissions both GD(P) and other. Some were told they couldn't until they had amortised their flying training, others were told to crack on. Those who pressed to test were eventually allowed so to do. It appears that you may be discouraged, but that ultimately you cannot be stopped (from applying that is). However, commisions for GD(P) are like rocking horse s*!t at the moment. Have a look around other threads on this forum. Best of luck either way.