Rant like a politician in fury (7)
I believe the answer is:
rampage
'rant' is the definition.
(thesaurus)
'a politician in fury' is the wordplay.
'politician' becomes 'MP' (Member of Parliament).
'in' is an insertion indicator.
'fury' becomes 'rage' (synonyms).
'a'+'mp'='amp'
'amp' placed inside 'rage' is 'RAMPAGE'.
'like' acts as a link.
(Other definitions for rampage that I've seen before include "Storm" , "Run wild" , "Rioting, for example" , "Go berserk" , "Rage wildly around" .)