Stuffy I've always been a serious A400M cheerleader, amazing machine.
But if it would up to Mr Airbus, they'll prefer an A320 NEO version. It has a usefull belly, more then enough cabin space and e.g. additional fuel tanks are off the shelf. It was discussed in the past. I guess many are waiting what the french will do. They have an old MPA fleet and fresh conflict insights. Airbus launched an A319 based MPA concept more the a decade ago for USN and India RFI 's.
A319 MPA Maritime Patrol Aircraft - Naval Technology
I think in the end UK, France, Germany will sit around the table and come to a joint basic MPA requirement.