Coppers on spot reported revolution (3,6)
I believe the answer is:
sea change
'spot reported revolution' is the definition.
The definition suggests a singular noun which matches the answer.
'coppers' is the wordplay.
I cannot quite understand how this works, but
'coppers' could be 'change' (I've seen this before) and 'change' is found within the answer.
The remaining letters 'sea' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'on' acts as a link.
Can you help me to learn more?
(Other definitions for sea change that I've seen before include "Significant transformation of marine origin" , "Profound transformation" , "Notable transformation" , "Significant or unexpected transformation - on the briny?" , "Major transformation" .)