Argument from Conservative whip (5)
I believe the answer is:
clash
'argument' is the definition.
(thesaurus)
'conservative whip' is the wordplay.
'conservative' becomes 'c' (abbreviation commonly used in UK politics).
'whip' becomes 'lash' ('lash' can be a synonym of 'whip').
'c'+'lash'='CLASH'
'from' is the link.
(Other definitions for clash that I've seen before include "Loud noise - conflict" , "Come into violent conflict" , "Fail to fit" , "Forceful disagreement" , "Conflict, between colours say" .)