Insists on starting rebellion in property (7)
I believe the answer is:
asserts
'insists' is the definition.
(asserting is a kind of insisting)
'starting rebellion in property' is the wordplay.
'starting' says to take the initial letters.
'in' indicates putting letters inside.
'property' becomes 'assets' (I've seen this before).
The initial letter of 'rebellion' is 'r'.
'r' put inside 'assets' is 'ASSERTS'.
'on' is the link.
(Other definitions for asserts that I've seen before include "States confidently and forcefully" , "States firmly" , "States categorically" , "Declares to be true" .)