Financial backer to support a run on church port (9)
I believe the answer is:
'port' is the definition.
(city and port in Archangelsk oblast, Russia)
'financial backer to support a run on church' is the wordplay.
'financial backer' becomes 'angel' (I've seen this before).
'to support' is a charade indicator (letters next to each other) (in a down clue, some letters hold others up).
'a run' becomes 'ar' (I've seen this in other clues**).
'on' is a charade indicator (letters next to each other).
'church' becomes 'ch' (common abbreviation).
'angel' put after 'arch' is 'ARCHANGEL'.
(Other definitions for archangel that I've seen before include "one coming from above with message maybe", "Among others, Michael", "Port in northern Russia, or senior heavenly messenger", "celestial flier", "Raphael, say".)