Hard work raising, through doubled oil production, the lower classes (3,6)
I believe the answer is:
hoi polloi
'hard work raising' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'doubled oil production the lower classes' is the wordplay.
I cannot really see how this works, but
an anagram of 'oil' is 'loi' which is present in the answer.
This may be the basis of the clue (or it may be nonsense).
'through' is the link.
Can you help me to learn more?
(Other definitions for hoi polloi that I've seen before include "The unwashed masses!" , "The common people generally" , "commoners" , "(Often derogatory) term for the masses or common people" , "ordinary people" .)