Boss upset by right-wing whinging (3,5)
I believe the answer is:
sob story
'whinging' is the definition.
(a sob story is a self-pitying story)
'boss upset by right-wing' is the wordplay.
'upset by' is an anagram indicator.
'right-wing' becomes 'Tory'.
'boss' is an anagram of 'sobs'.
'sobs'+'tory'='SOB-STORY'
(Other definitions for sob story that I've seen before include "Victim's tale?" , "Account intended to evoke sympathy" , "A tale of woes" , "Account intended to arouse sympathy" , "tale of woe" .)