Misrepresent a lot of party upset over legal wrong (7)
I believe the answer is:
distort
'misrepresent' is the definition.
(I know that distort is a more specific form of the action misrepresent)
'a lot of party upset over legal wrong' is the wordplay.
'a lot of' means to remove the last letter (most of the word but not all of it).
'party' becomes 'side' (eg a side or party in a contract).
'upset over' says the letters should be written backwards (knocked over).
'legal wrong' becomes 'tort' (I've seen this before).
'side' with its last letter taken off is 'sid'.
'sid' in reverse letter order is 'dis'.
'dis'+'tort'='DISTORT'
(Other definitions for distort that I've seen before include "Deform" , "Warp" , "bend" , "Twist out of shape" , "Pervert" .)