Britain gets positive response for some extras (4)
I believe the answer is:
byes
'some extras' is the definition.
(I've seen this before)
'britain gets positive response' is the wordplay.
'britain' becomes 'B' (common abbreviation as in GB).
'gets' is a charade indicator (letters next to each other).
'positive response' becomes 'yes' (positive response to a question).
'b'+'yes'='BYES'
'for' acts as a link.
(Other definitions for byes that I've seen before include "In cricket, runs scored from balls that pass the batman without being hit" , "Cricketing extras" , "Runs not from bat" , "Wicketkeeper's concession" , "Greedy person; seabird" .)