Unqualified to speak (5)
I believe the answer is:
utter
This clue is a double definition.
'unqualified' is the first definition.
(I've seen this before)
'speak' is the second definition.
(I know that speak can be written as utter)
'to' is the link.
(Other definitions for utter that I've seen before include "Absolutely" , "Express; complete" , "Speak, articulate" , "Say the words" , "Absolute - say" .)