Disheartened people stood for election with miners each year (3,5)
I believe the answer is:
per annum
'each year' is the definition.
('per annum' can be a synonym of 'each year')
'disheartened people stood for election with miners' is the wordplay.
'disheartened' suggests removing the centre.
'stood for election' becomes 'ran' (I've seen this before).
'with' is a charade indicator (letters next to each other).
'miners' becomes 'num'.
'people' with its centre taken out is 'pe'.
'pe'+'ran'+'num'='PER ANNUM'
(Other definitions for per annum that I've seen before include "For each year - in Latin" , "Yearly" .)