Supports the move to have the incentive raised (8)
I believe the answer is:
stirrups
'supports' is the definition.
(stirrup is a kind of support)
'move to have the incentive raised' is the wordplay.
'move' becomes 'stir' (stir can mean to make a movement).
'to have' means one lot of letters go next to another.
'the incentive' becomes 'spur' (an incentive spurs someone on).
'raised' is a reversal indicator (going up in a down clue).
'spur' reversed gives 'rups'.
'stir'+'rups'='STIRRUPS'
'the' acts as a link.
(Other definitions for stirrups that I've seen before include "Riding equipment" , "Metal loops for rider's feet" , "Metal loops for a rider" , "Horsemen put their feet in them" , "Bones" .)