In B&B need the whole bar (9)
I believe the answer is:
blackball
'bar' is the definition.
(blackball can mean to bar or block)
'in bb need the whole' is the wordplay.
'in' means one lot of letters goes inside another.
'need' becomes 'lack' (to lack something is to be in need of it).
'the whole' becomes 'all' (I've seen this before).
'bb' enclosing 'lack' is 'blackb'.
'blackb'+'all'='BLACKBALL'
(Other definitions for blackball that I've seen before include "Reject" , "Refuse to endorse" , "Veto (membership)" , "Shut out (of a group)" , "Vote against would-be member" .)