Hmmmm, how about a flat rate per diem, with a varying amount depending on what country you're in? You could call it, I don't know, a "rate" perhaps? Nice and simple, with no arguements or "confusions".
Not to defend those that deliberately set out to embezzle the tax-payer but this does look like a case of the brass back-slapping themselves by introducing JPA/Capped actuals (with obscure advice over what is within ones entitlement) in the hope of shaving £Ms off the T&S budget, and now complaining that savings targets aren't being met. At the same time, they ensure it's first-class all the way with PSOs/ADCs exploiting every loophole quicker than a Herc mate at a check-in desk....
I do wonder if this (along with the disgraceful "perks" nonsense last month) is "shaping the battlefield" for the removal of the CEA.
As for Richards getting involved..I'd of thought that getting his troops out of Snatch landrovers is a better use of his time. Clamping down on T&S and Allowances is not going to solve the chasm in the Departments finances.