Well he could just look at the Carrier thread on here where quite a few people (including me) bewail the distorting effect of the Carriers on the RN.
But as you say that is going to be a tough sell - maybe they 'll buy F35A's instead of B's to save some cash..................... but it's still hard to see one that will generate significant savings... and of course "savings" suggests that the money will come out of the Military Budget and be spent on bribes to those hit by BREXIT