One may be spoilt for choice in an election (6,5)
I believe the answer is:
ballot paper
'one may be spoilt' is the definition.
'choice in an election' is the wordplay.
'choice' becomes 'ballot' (ballot is a kind of choice).
'in an election' becomes 'paper' (I can't explain this - if you can you should give a lot more credence to this answer).
'ballot'+'paper'='BALLOT PAPER'
'for' is the link.
(Other definitions for ballot paper that I've seen before include "On which to record one's vote" , "Voting slip" .)