Rebellious MPs score in squeeze (8)
I believe the answer is:
compress
'squeeze' is the definition.
(I know that squeeze can be written as compress)
'rebellious mps score' is the wordplay.
'rebellious' is an anagram indicator.
'mps'+'score'='mpsscore'
'mpsscore' with letters rearranged gives 'COMPRESS'.
'in' is the link.
(Other definitions for compress that I've seen before include "Squeeze into less space" , "Make more compact" , "Flatten by pressure" , "Crush" , "Squeeze; a staunching pad" .)