Support fraud in subordinate role (6,6)
I believe the answer is:
second fiddle
'subordinate role' is the definition.
(I've seen this before)
'support fraud' is the wordplay.
'support' becomes 'second' (eg to second an idea is to support it).
'fraud' becomes 'fiddle' (I've seen this before).
'second'+'fiddle'='SECOND FIDDLE'
'in' acts as a link.
(Other definitions for second fiddle that I've seen before include "Player's attendant" , "Dry" , "Junior player" , "junior role" , "In which role Clegg" .)