Published call for protest (6)
I believe the answer is:
outcry
'for protest' is the definition.
(I've seen this before)
'published call' is the wordplay.
'published' becomes 'out' (I've seen this in other clues).
'call' becomes 'cry' (as in a bird's call).
'out'+'cry'='OUTCRY'
(Other definitions for outcry that I've seen before include "A storm of protest" , "Exclamation - clamour" , "Exclamation, shout" , "Exclamations of opposition" , "Vociferous protest" .)