Whip starts to look absolutely ridiculous, really upsetting parliamentarians (6)
I believe the answer is:
larrup
'whip' is the definition.
(thesaurus)
'starts to look absolutely ridiculous really upsetting parliamentarians' is the wordplay.
'starts to' indicates taking the first letters.
The first letters of 'look absolutely ridiculous really upsetting parliamentarians' is 'LARRUP'.
(Other definitions for larrup that I've seen before include "Flog" , "Hit hard" .)