Double secret spies. Ahmaneedanewsportscoat has apparently caught on to the spy in uniform cover.
I think the next move is for Britain to seize and hold all occupants of the Iranian Embassy in Britain for "activities out of keeping with their diplomatic status" and indict them as spies. If Imanutjob complains about "violation of sovereignty, publish the photos". In any case, say "Since Iran does not recognize international boundaries, and since these persons were well within British Territory, they will be tried as spies. The Geneva convention protects persons captured in uniform, but permits the immediate execution of non-uniformed spies. We will conduct ourselves in accord with the Geneva Conventions."