Bush to refuse to accept letter from old England (10)
I believe the answer is:
blackthorn
'bush' is the definition.
(blackthorn is a kind of bush)
'refuse to accept letter from old england' is the wordplay.
'refuse to accept' becomes 'black' (as in blacking or boycotting a business).
'letter from old england' becomes 'thorn' (historical letter of the alphabet).
'black'+'thorn'='BLACKTHORN'
'to' is the link.
(Other definitions for blackthorn that I've seen before include "Sloe bush" , "Sloe-bearing bush" , "Tree producing sloes" , "Tree bearing sloes" , "Sloe-bearing shrub" .)