Repeated invitation that I cannot accept! (4,4)
I believe the answer is:
come come
'that i cannot accept' is the definition.
(said in response to something one disapproves of)
'repeated invitation' is the wordplay.
'repeated' says to double the letters.
'invitation' becomes 'come' (an invitation to come).
'come' doubled is 'COME COME'.
(Other definitions for come come that I've seen before include "that's not good enough" , "Remonstrance" , "Expr. of mild reproof" , "Be reasonable!" .)