Complaints caused by Conservative-Liberal relationship (7)
I believe the answer is:
clamour
'complaints' is the definition.
(I've seen this before)
'conservative-liberal relationship' is the wordplay.
'conservative' becomes 'C' (UK political abbreviation).
'liberal' becomes 'l' (abbreviation).
'relationship' becomes 'amour' (amour is a kind of relationship).
'c'+'l'+'amour'='CLAMOUR'
'caused by' acts as a link.
(Other definitions for clamour that I've seen before include "Loud confused noise" , "row" , "Hue and cry" , "Din and commotion" , "Loud and persistent outcry" .)