Representative in power in disorder (6)
I believe the answer is:
rumple
'disorder' is the definition.
(thesaurus)
'representative in power' is the wordplay.
'representative' becomes 'mp'.
'in' indicates putting letters inside.
'power' becomes 'rule' (rule is a kind of power**).
'mp' inserted inside 'rule' is 'RUMPLE'.
'in' is the link.
(Other definitions for rumple that I've seen before include "mess" , "Make untidy, say clothes" , "Wrinkle, make uneven" , "Disturb the smoothness" , "Dishevel, ruffle" .)