Previously supported by church (4)
I believe the answer is:
once
'previously' is the definition.
(thesaurus)
'supported by church' is the wordplay.
'supported by' becomes 'on'.
'church' becomes 'ce' (abbreviation for Church of England).
'on'+'ce'='ONCE'
(Other definitions for once that I've seen before include "In the old days" , "in bygone days" , "yesterday" , "Quick examination" , "Formerly - not repeated" .)