Attempt to discredit press cameraman — pigs! (5,8)
I believe the answer is:
smear campaign
'attempt to discredit' is the definition.
(I've seen this before)
'press cameraman pigs' is the wordplay.
'press' indicates an anagram (I've seen 'pressed' mean this (the letters are pressed into a new order)).
'cameraman'+'pigs'='cameramanpigs'
'cameramanpigs' is an anagram of 'SMEAR CAMPAIGN'.
(Other definitions for smear campaign that I've seen before include "Manager is camp (anag)" , "Organised vilification" , "Course of action to discredit someone" , "Negative propaganda aimed at damaging a person's reputation" , "Concerted operation to sully someone's name" .)