See CAP 804 Part I Section 4 Part P pp48-50 (.pdf pp 580-582) - you too, Tay Cough!.
Also no military flight training before graduating from EFT is allowable towards the part-FCL PPL. However, if you can get to test standard and apply before 8 Apr 2018, military flight training time can be used towards the NPPL(SSEA) - which can then be converted to a LAPL and ultimately to a PPL.