Withdraw from diocese that includes church close to Bradford (6)
I believe the answer is:
secede
'withdraw from' is the definition.
(as in seceding from an organisation)
'diocese that includes church close to bradford' is the wordplay.
'diocese' becomes 'see' (I've seen this before).
'that includes' is an insertion indicator.
'church' becomes 'CE' (abbreviation for Church of England).
'close to' says to take the final letters (the close/ending of).
The final letter of 'bradford' is 'd'.
'ce'+'d'='ced'
'see' enclosing 'ced' is 'SECEDE'.
(Other definitions for secede that I've seen before include "Disaffiliate" , "Withdraw (from a federal union or organisation)" , "Formally withdraw (from federal union)" , "Withdraw formally from membership or alliance" , "Formally achieve independence" .)