Maybe Corbyn's embracing Labour's leader - they might have clenched teeth (6)
I believe the answer is:
pliers
I'm afraid I can't even guess how this answer relates to the clue.
Can you help me to learn more?
(Other definitions for pliers that I've seen before include "Workmen's tools" , "Gripping tool with two serrated jaws" , "Nippers" , "Gripping tool, kind of pincers" , "Pinching or gripping tool" .)