Eventually a question of priority (6,2,5)
I believe the answer is:
sooner or later
'eventually' is the definition.
(synonyms)
'a question of priority' is the wordplay.
I cannot quite understand how this works, but
'a' could be 'one' and 'one' is found in the answer.
'of' could be 'o' and 'o' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for sooner or later that I've seen before include "offering alternative times" , "not on the dot" , "At some point" , "Inevitably" , "Errors (a lot) one corrected, eventually" .)