Vld
Here you go. You want pages 6-9 and 6-10.
The basic principle is now that the Armed Forces are not to be used to bailout other government departments who have mismanaged their budgets/spending plans. If the Armed Forces are called in to help, then the relevant OGD is billed for the services provided. The exception is obviously when the situation is life-threatening or in emergency.
Edited to add:
Even better try this:
JDP 02 It has all the answers you might be looking for.