Remember to pass in vote at the end of winter (9)
I believe the answer is:
recollect
'remember' is the definition.
(I know that remember can be written as recollect)
'pass in vote at the end of winter' is the wordplay.
'pass' becomes 'col' (col is a term for a mountain pass).
'in' means one lot of letters goes inside another.
'vote' becomes 'elect' ().
'at' is a charade indicator (letters next to each other) (I've seen this in other clues).
'the end of' says to take the final letters.
The last letter of 'winter' is 'r'.
'col' placed into 'elect' is 'ecollect'.
'ecollect' put after 'r' is 'RECOLLECT'.
'to' acts as a link.
(Other definitions for recollect that I've seen before include "Reminisce" , "Remember" , "Recall to mind" , "Flock together again" , "Bring back to mind." .)