It would be imprudent not to develop this. If your adversary deploys this technology they would have a dramatic advantage against you. Like nukes its technology that should not be used, but you also don't want to be the one without it.
A spokesman for the MoD said: “There is no intent within the MOD to develop weapon systems that operate entirely without human input. Our weapons will always be under human control as an absolute guarantee of oversight, authority and accountability.”