Roland Pulfrew, Airbus originally proposed an A320 MPA for the German Navy:
But instead they acquired ex-Dutch Navy P-3Cs which now equip Marinefliegergeschwader 3
Graf Zeppelin.
Airbus later refined the design proposal in an A319 MPA which lost out to the P-8I for India.
I would have thought that a 'sharklet' A321 MPA would offer greater fuel capacity (if modified to include additional tanks) - and the advantage of similar type ratings for the A321 MPA and Voyager might reduce training costs significantly. Where to base them? Well, when Cornwall finally accepts that Newquay Airport is unsustainable, perhaps the RAF could return to St. Mawgan?