Bishop, opposition leader, sculptor and composer (7)
I believe the answer is:
borodin
'composer' is the definition.
(Alexander Borodin was a Russian composer)
'bishop opposition leader sculptor' is the wordplay.
'leader' says to take the initial letters.
'sculptor' becomes 'rodin' (Auguste Rodin was a French sculptor).
The initial letters of 'bishop opposition' is 'bo'.
'bo'+'rodin'='BORODIN'
'and' is the link.
(Other definitions for borodin that I've seen before include "Russian composer, Aleksandr Porfirevich (1834-87)" , "Russian composer (Prince Igor)" , "Noteworthy chap" , "Russian composer, d. 1887" , "Prince Igor composer, d. 1887" .)