Firm policy when politician's put in an hour of prayer! (8)
I believe the answer is:
compline
'prayer' is the definition.
(thesaurus)
'firm policy when politician's put in an hour' is the wordplay.
I cannot quite understand how this works, but
'firm' could be 'co' (a firm is a company) and 'co' is located in the answer.
'policy' could be 'line' (as in the party line) and 'line' is found in the answer.
'politician' could be 'mp' (Member of Parliament) and 'mp' is found in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'of' is the link.
Can you help me to learn more?
(Another definition for compline that I've seen is " Monks' last hour".)