Refuse to allow a free vote (4)
I believe the answer is:
veto
'refuse to allow' is the definition.
(I've seen this before)
'a free vote' is the wordplay.
'a free' indicates an anagram.
'vote' with letters rearranged gives 'VETO'.
(Other definitions for veto that I've seen before include "negative result" , "Forbid outright" , "Refusal to assent" , "Right to ban" , "Embargo" .)