PM put on edge in chaos (6)
I believe the answer is:
mayhem
'chaos' is the definition.
(thesaurus)
'pm put on edge' is the wordplay.
'pm' becomes 'may' (Theresa May).
'put on' is a charade indicator (letters next to each other).
'edge' becomes 'hem' (I've seen this before).
'may'+'hem'='MAYHEM'
'in' acts as a link.
(Other definitions for mayhem that I've seen before include "Violent or damaging action, a crime" , "Violent damage, chaos" , "Chaos, violent disorder" , "Scene of great disorder" , "violence" .)