Fail to impress count abroad with diamonds (3,2,3)
I believe the answer is:
cut no ice
'fail to impress' is the definition.
(I've seen this before)
'count abroad with diamonds' is the wordplay.
'abroad' indicates anagramming the letters.
'with' means one lot of letters go next to another.
'diamonds' becomes 'ice' (I've seen this before).
'count' with letters rearranged gives 'cutno'.
'cutno'+'ice'='CUT NO ICE'
(Other definitions for cut no ice that I've seen before include "Fail to split frozen water and count or nothing" , "Be ineffective" , "Fail to impress" , "Blunt skates will" , "Not make any impression" .)