Gin most of Labour perhaps rejected (4)
I believe the answer is:
trap
'gin' is the definition.
(I've seen this in other clues)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for trap that I've seen before include "Snare - mouth" , "Light horse-drawn carriage" , "Bunker; carriage" , "Means of transport (sometime sprung!)" , "Part of a snare" .)