MP: Half of (the opposition) are crooks / Speaker: Please ____ / MP: OK. Half of (the opposition) are not crooks (old joke) (7)
I believe the answer is:
retract
(Other definitions for retract that I've seen before include "Abjure" , "Withdraw, take back" , "Take back (statement)" , "Pull back (statements or claws, perhaps)" , "Withdraw as unjustified" .)