Jailbird before the bench has to toe the line (7)
I believe the answer is:
conform
'to toe the line' is the definition.
(I've seen this before)
'jailbird before the bench' is the wordplay.
'jailbird' becomes 'con' (I've seen this in other clues).
'before' says to put letters next to each other.
'the bench' becomes 'form' (I've seen this before).
'con'+'form'='CONFORM'
'has' is the link.
(Other definitions for conform that I've seen before include "Run with the pack" , "Toe the line" , "Follow the crowd" , "Agree" , "Comply with accepted rules" .)