Run wild in anger about an MP (7)
I believe the answer is:
rampage
'run wild' is the definition.
(I've seen this before)
'anger about an mp' is the wordplay.
'anger' becomes 'rage' (rage is a kind of anger).
'about' means one lot of letters goes inside another.
'an' becomes 'a'.
'a'+'mp'='amp'
'rage' placed around 'amp' is 'RAMPAGE'.
'in' acts as a link.
(Other definitions for rampage that I've seen before include "Go berserk" , "Frenzy" , "Rush around violently and uncontrollably" , "destructive behaviour" , "Storm" .)