Set up Labour's underlying structure? (9)
I believe the answer is:
framework
'underlying structure?' is the definition.
(I've seen this before)
'set up labour's' is the wordplay.
'set up' becomes 'frame' ('frame' can be a synonym of 'set up'**).
'labour' becomes 'work' (I've seen this before).
'frame'+'work'='FRAMEWORK'
(Other definitions for framework that I've seen before include "Underlying structure" , "Structure, skeleton" .)